HSH746/HSH946 Biostatistics 1ppr

HSH746/HSH946
Biostatistics 1
Paper 1
Examination Time: 2 hours
Anticipated Working Time: 1 hour
Preparation time: 1 hour (Note that this includes the usual 15mins reading time, as well as time to
download/upload exam papers into CloudDeakin etc. This additional time also reflects the current
climate in which you are experiencing this type of online exam for the first time.)
Instructions for Candidates:
Open Book Online Examination. Calculators Allowed.
All Deakin students are expected to act with academic integrity in accordance with the student academic
integrity policy and procedure. For this open-book online examination, this means you must submit
your own work without input or assistance from anybody else. We have invested in new systems for
detecting when students use unauthorised material during assessment or submit work which is not their
own. Please be aware you may be asked to answer questions about your submitted work, and students
found to have cheated will face severe penalties. These can include being excluded from Deakin or not
being awarded your degree.
All candidates MUST complete this section:
ID Number:
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 2 of 19
[HSH746/HSH946 Biostatistics 1]
Example questions – Online Examination
Trimester 1, 2020
Special Instructions
This examination is OPEN BOOK.
Calculators are ALLOWED.
Anticipated writing time is 2 HOURS.
Preparation time: 1 hour (Note that this includes the usual 15mins reading time, as well as time to
download/upload exam papers into CloudDeakin etc. This additional time also reflects the current climate
in which you are experiencing this type of online exam for the first time.)
This examination comprises 33 questions. You are required to answer 3 questions in short answer format.
Please use this template for your written responses, making sure that each question is clearly numbered.
This examination constitutes 50 % of your assessment in this unit.
If you encounter any technical issues with CloudDeakin, please contact the IT Service Desk online or via
phone (1800 463 888; +61 3 5227 8888 if calling from outside Australia) and record your ticket number as
evidence of technical issues during the examination period.
The completed examination document must be submitted via the relevant assignment
dropbox in CloudDeakin.
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 3 of 19
Multiple choice questions (MCQ)
Title: ExamP1-Set01-Q01
1. A researcher wishes to investigate the relationship between job type and job satisfaction in a large
organisation. She wishes to select a sample of employees from that organisation and interview
them about their jobs and ask about their satisfaction levels. This organisation comprises a head
office and a large number of different factories in various locations around the country. The
researcher can’t afford to visit every factory, so she selects a sample comprising the head office
and a random sample of the factories. She suspects that job satisfaction may be different between
urban and rural areas, so she divides up the list of factories into urban and rural groups and selects
her sample separately from the two groups. She plans to interview employees from the head
office and each of the selected factories. In this sample the organisation’s employees are:
a. The sampling frame
b. The study sample
c. Target Population
d. The Clustering set
Title: ExamP1-Set01-Q02
2. A researcher wishes to investigate the relationship between job type and job satisfaction in a large
organisation. She wishes to select a sample of employees from that organisation and interview
them about their jobs and ask about their satisfaction levels. This organisation comprises a head
office and a large number of different factories in various locations around the country. The
researcher can’t afford to visit every factory, so she selects a sample comprising the head office
and a random sample of the factories. She suspects that job satisfaction may be different between
urban and rural areas, so she divides up the list of factories into urban and rural groups and selects
her sample separately from the two groups. She plans to interview employees from the head
office and each of the selected factories. What type of sampling method is used in this study?
a. Simple random sampling
b. Clustered random sampling
c. Stratified sampling
d. Convenience sampling
Title: ExamP1-Set01-Q03
3. In a study, a researcher collects data from each person in the sample on their history of heart
attack, stroke, high blood pressure, exercise habits, and dietary habits. Initially we want to
estimate the effect of exercise and diet on stroke. Which of the following best describes the
variables the researcher will use in her analysis?
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 4 of 19
a. Stroke is the outcome variable and exercise and diet are the exposure variables.
b. Heart attack and stroke are both outcome variables and exercise and diet are the exposure variables.
c. High blood pressure, heart attack and stroke are all outcome variables and exercise and diet are the
exposure variables.
d. Heart attack and stroke are both outcome variables and high blood pressure, exercise and diet are
the exposure variables.
e. Stroke is the outcome variable and high blood pressure, exercise and diet are the exposure variables.
Title: ExamP1-Set01-Q04
4. A researcher is investigating the wellbeing of young single mothers at a university in Sydney. The
findings from this study can be generalized to the population of:
a. All young single mothers at that university
b. All young single mothers at all the universities in Sydney
c. All young single mothers who go to university in Australia
d. All young single mothers in Sydney
Title: ExamP1-Set02-Q01
5. The National Health Survey (NHS) is evaluating the health and nutrition status of adults in
Australia. As a part of the survey a range of demographic characteristics and health related data
were collected. One of the variables collected in this survey was income quintile. What type of
variable is income quintile?
a. Quantitative continuous
b. Quantitative discrete
c. Categorical ordinal
d. Categorical nominal
Title: ExamP1-Set02-Q02
6. The National Health Survey (NHS) is evaluating the health and nutrition status of adults in
Australia. As a part of the survey a range of demographic characteristics and health related data
were collected. Age was recorded as age in years. What type of variable is age?
a. Quantitative continuous
b. Quantitative discrete
c. Categorical ordinal
d. Categorical nominal
Title: ExamP1-Set02-Q03
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 5 of 19
7. You have the following sample of ten numbers – 85, 80, 72, 76, 30, 20, 35, 10, 25, 15. The mean of
this sample to 1 decimal place is
a. 25
b. 32.5
c. 44.8
d. 30
Title: ExamP1-Set02-Q04
8. You have the following sample of ten numbers – 85, 80, 72, 76, 30, 20, 35, 10, 25, 15. The median of
this sample to 1 decimal place is
a. 25
b. 32.5
c. 44.8
d. 30
Title: ExamP1-Set03-Q01
9. Suppose you have a sample of Australian adults for whom you record age, grouped into five year age
groups, and number of people reporting having hypertension (in hundreds). Which of the following
best describes the best way to present these data?
a. We should plot the data in a pie chart.
b. We should plot the data in a histogram.
c. We should plot the data in a box plot.
d. We should plot the data in a bar chart.
Title: ExamP1-Set03-Q02
10. Suppose you have a sample of people for whom you record smoking status (coded as 1 for smoking
and 0 for non-smoker) and gender (coded as 0 females and 1 for males). Which of the following best
describes an appropriate way to present these data?
a. We should plot the data in a box plot.
b. We should calculate a mean and standard deviation.
c. We should present the data in a table.
d. We should plot the data in a pie chart.
e. We should calculate a median and inter quartile range.
Title: ExamP1-Set03-Q03
11. Which of the following statements best describes the normal distribution?
a. The normal distribution is uniquely identified by its mean and standard deviation.
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 6 of 19
b. The normal distribution can only be transformed to the standard normal distribution if it has a nonzero mean.
c. The normal distribution has both a positive and a negative skew.
d. The normal distribution can be transformed to the standard normal distribution using the log
transformation.
e. If the mean is equal to the median, then we can assume that the distribution is normal.
Title: ExamP1-Set03-Q04
12. How do we use the standard normal distribution?
a. To calculate probabilities for data that has been transformed to a standard normal distribution
b. To calculate the Z score for data with big sample size
c. To transform skewed data to the normal distribution
d. To calculate probabilities for data with big sample size
Title: ExamP1-Set04-Q01
13. You have selected a sample of men and women from a population group. The 95% confidence interval
for the mean height (in centimeters) for the sample of women is (149, 163) and for the sample of men
is (161, 182). Which of the following statements best describes the relationship between mean heights
in men and women?
a. The mean height for the women is lower than the mean height of men
b. The mean height for the women is higher than the mean height of men
c. The data does not provide any evidence that the mean height is different between men and women
d. The mean height of the men and women are same.
Title: ExamP1-Set04-Q02
14. You have two samples of babies under 1 year old selected to be representative of two population
groups. The 95% confidence interval for the mean weight (in kilograms) for the first sample is (11, 14)
and for the second sample is (10, 13). Which of the following statements best describes the
relationship between the mean weight in the two population groups?
a. The mean height for the first group is higher than the mean height for the second group.
b. The mean weight for the first group is lower than the mean weight for the second group.
c. The mean weight for the first group is equal to the mean weight for the second group.
d. The ranges of plausible values for the mean in each group overlap.
Title: ExamP1-Set04-Q03
15. A 95% confidence interval estimate for the difference between two population means µ1-µ2, is
determined to be (52.61, 68.52). If the confidence level is reduced to 90%, the confidence interval
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 7 of 19
a. Remains the same
b. Becomes narrower
c. Becomes wider
d.We can’t determine how it changes without more information
Title: ExamP1-Set04-Q04
16. You have two samples of women selected to be representative of two population groups. The 95%
confidence interval for the mean height (in centimetres) for the first sample is (154, 163) and for the
second sample is (162, 183). Which of the following statements best describes the relationship
between the mean heights in the two population groups?
a. The mean height for the first group is higher than the mean height for the second group.
b. The mean height for the first group is lower than the mean height for the second group.
c. The mean height for the first group is different to the mean height for the second group.
d. The data does not provide any evidence that the mean height is different between the two groups
Title: ExamP1-Set05-Q01
17. You conduct a small trial of a new treatment for lung cancer. The mortality in the group with the new
treatment was half that in the group with the current standard treatment. However, the difference
was not statistically significant. Which of the following statements best describes your conclusion
from this trial?
a. The new treatment is no better than the old treatment.
b. Further study of the new treatment would be unethical as it has been shown to be no better than the
old treatment.
c. The reduction in mortality is so great that we can overlook the lack of statistical significance and
conclude that the new treatment is better than the old treatment.
d. The reduction in mortality is so great that we can overlook the lack of statistical significance and focus
our future research on the new treatment.
e. We should carry out a new trial with a greater sample size before we can make reliable conclusions
about comparisons between the old and new treatments.
Title: ExamP1-Set05-Q02
18. A research project investigated the association between hypertension and sex (1=male, 2 = female) to
estimate the difference in mean hypertension. The Stata output below indicates the results of a ttest
from this research. Which of the following best describes your conclusion from the results of this test?
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 8 of 19
a. The confidence interval for the difference between mean hypertension for males and the mean
hypertension for females contains zero. So, our data do not give us evidence that there is any difference
in the population mean hypertension value for males and for females.
b. The confidence interval for the difference between mean hypertension for males and the mean
hypertension for females contains negative values. So, our data do not give us evidence that there is any
difference in the population mean hypertension value for males and for females.
c. The difference between mean hypertension for males and the mean hypertension for females is not
equal to zero. So, our data provides evidence that there is a difference in the population mean
hypertension value for males and females.
d. The difference between mean hypertension for males and the mean hypertension for females is equal
to zero. So, our data provides evidence that mean hypertension for males and mean hypertension for
females is equal.
Title: ExamP1-Set05-Q03
19. A research project investigated the association between hypertension and sex (1=male, 2 = female) to
estimate the difference in mean hypertension. The Stata output below indicates the results of a ttest
from this research. Which of the following best describes the use of the normal distribution for this
sample?
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 9 of 19
a. the assumption of the sampling distribution being normal does not hold because both our samples have
sample size less than 30
b. the assumption of the sampling distribution being normal does hold because the sample standard
deviation is a good estimate of the population standard deviation
c. the assumption of the sampling distribution being normal does hold because our sample has
approximately 30 observations
d. the assumption of the sampling distribution being normal does hold because the sample standard
error is a good estimate of the population standard error
Title: ExamP1-Set06-Q01
20. The following graphs represent normal quantile plots for two samples, each of size 20. Which of
the following statements best describes these samples?
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 10 of 19
a. Sample 1 is approximately normally distributed but sample 2 is not.
b. Sample 2 is approximately normally distributed but sample 1 is not.
c. Both samples are approximately normally distributed.
d. Neither sample is approximately normally distributed.
e. We can’t tell whether or not the data are normally distributed because the sample sizes are less
than 30
Title: ExamP1-Set06-Q02
21. A hypothesis test comparing the mean birthweight for babies between a group of mothers who
are adolescents (<18 years) and a group of mothers who are adults (>18 years) gives a t statistic of
4.2 with 126 degrees of freedom and p value of <0.001. Which of the following statements best
describes your conclusion from this test?
a. We have proved that the means of the two groups are the same.
b. We have proved that the means of the two groups are different.
c. We accept the null hypothesis that the means of the two groups are the same.
d. We reject the null hypothesis that the means of the two groups are the same.
e. The p value is too small for us to draw any conclusion from this test.
Title: ExamP1-Set06-Q03
22. Which of the following statements best describes what we are attempting to do when we perform
a hypothesis test?
a. We are attempting to prove the null hypothesis.
b. We are attempting to disprove the null hypothesis.
c. We are looking to see if our data provide evidence for the null hypothesis.
d. We are looking to see if our data provide evidence against the null hypothesis.
-1 0 1 2 3
sample2
-1 0 1 2 3
Inverse Normal
Sample 2
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 11 of 19
Title: ExamP1-Set07-Q03
23. A study of the effect of an exercise intervention on obesity followed a cohort of 1,500 people over
a year. Their obesity category at baseline (before the intervention) and after 12 months is
presented in table 1. You wish to test whether or not the intervention had an effect on obesity.
Which of the following statements best describes the appropriate test?
a. You use a chi square test with 4 degrees of freedom.
b. You use a chi square test with 1 degree of freedom.
c. You use McNemar’s test with 1 degree of freedom
d. You use McNemar’s test with 4 degrees of freedom.
e. The data are not independent, because the same people contributed data at both baseline and follow
up, so neither the chi square nor McNemar’s test is appropriate.
Title: ExamP1-Set07-Q04
24. You want to test the association between prevalence of diabetes and gender. The following is the
output of a chi-squared test. Which of the following statements best describes the association
between these variables?
a. You use a chi square test with 2 degree of freedom and associated p-value is 0.471
b. You use a chi square test with 1 degree of freedom and associated p-value is 0.5188
c. There is no statistically significant association between prevalence of diabetes and gender
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 12 of 19
d. There is a statistically significant association between prevalence of diabetes and gender
Title: ExamP1-Set08-Q03
25. Suppose you conducted a prtest to get an estimate of the difference in the proportion of children
diagnosed with influenza between those who were vaccinated and those who weren’t, along with
a 95% confidence interval. You tested the hypothesis that there is no difference in the proportion
of children with influenza between these two groups (vaccinated or not vaccinated). Stata results
are given below. Which of the following statements best describes your conclusion?
a. We accept the null hypothesis that there is no difference in prevalence of influenza between children
with and without vaccination.
b. We reject the alternative hypothesis and conclude that there is a statistically significant difference in
prevalence of influenza between children with and without vaccination.
c. We reject the null hypothesis and conclude that there is a statistically significant difference in
prevalence of influenza between children with and without vaccination.
d. The difference is statistically significant at 1% level because the 95% confidence interval for the mean
difference of the prevalence of influenza between vaccinated and not vaccinated does contain zero.
Title: ExamP1-Set08-Q04
26. Suppose you have a sample of children and have data on flu prevalence and flu-vaccination status.
You calculated the odds ratio of contracting flu for vaccinated vs not vaccinated. Using results from
Stata output, which of the following statements best describes your conclusion?
INSERT IMAGE ExamP1_Set08_Q04
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 13 of 19
a. We accept the null hypothesis and conclude that odds ratio is not statistically significantly different to
1 at 1% level.
b. We reject the null hypothesis and conclude that odds ratio is statistically significantly different to 1 at
1% level.
c. We accept the null hypothesis and conclude that odds ratio is not statistically significantly different to
0 at 1% level.
d. We reject the null hypothesis and conclude that odds ratio is statistically significantly different to 0 at
1% level.
Title: ExamP1-Set08-Q05
27. You have set a target of 50% for the proportion of children in a school to be vaccinated. You take a
sample of 50 children and identify which of the children in your sample is vaccinated – so the
variable vaccine is set to 1 for those children who are vaccinated and set to 0 for those children
who are not vaccinated. The following is the output of a Stata prtest procedure run on your
sample. Which of the following statements best describes your conclusions from the results of this
prtest.
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 14 of 19
a. The data do not show that you have failed to meet your target because the 95% confidence interval
contains 50%.
b. You have not yet met your target because the proportion of children in your sample who are
vaccinated is 46%, which is less than the target value of 50%.
c. You have met your target because the 95% confidence interval contains 50%.
d. You have not yet met your target because the p value is 0.5716, so your result is not statistically
significant.
Title: ExamP1-Set09-Q02
28. In a regression equation, the dependent variable is:
a. the variable used to explain the response/outcome variable
b. a variable whose value depends on the response variable
c. the variable we wish to predict or explain
d. the variable used to explain the independent variable
e. a and d
Title: ExamP1-Set09-Q03
29. Which of these variables would you expect to be associated with an increase in y?
a. Variables x1 and x2
b. all that are positively correlated to y (x1 x2 x5 and x6)
c. variables x3 and x4 since they are negatively correlated to y
d. variables x2, x5 and x6 since they have a low correlation with y
e. variable x1 since it has a moderate correlation with y
Title: ExamP1-Set09-Q06
30. Suppose you fit a bivariate regression model of weight (Y) on height (X). R-square value of your
regression model is 0.49. Which of the following is most appropriate statement based on regression
output?
a. The correlation coefficient between X and Y is 0.7
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 15 of 19
b. The correlation coefficient between X and Y is -0.7
c. The correlation coefficient between X and Y is 0.49
d. The correlation coefficient between X and Y is either 0.7 or –0.7
e. The correlation coefficient between X and Y is 0.
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 16 of 19
Section B Written Responses (manually graded)
Title: ExamP1-Set31-Q01a
31. You are interested in the association between birth weight and BMI among children aged 12-17 years
from a sub-sample of the 2018 National Health Interview Survey. You fit a regression equation using
average birthweight (kgs) as a predictor variable and average BMI (kg/m2) as the dependent variable. The
output from this regression is given below (10 marks)
a. What is the regression equation (reported to 2 decimal places)? (1 mark)
b. What does the equation mean in words? (1 mark)
c. Test the hypothesis that the coefficient for the predictor variable is zero and fully report the results.
(4 marks)
d. Is this equation a good predictor of BMI? What do you conclude? (4 marks)
——————————————————————————–
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 17 of 19
Title: ExamP1-Set32-Q01a
32. The graph shows the distribution of the birthweight of 2000 children aged 0-17 years old from a
sub-sample of the 2018 National Health Institute Study.
a. What type of variable is birthweight? (1 mark)
b. Using the graph, how would you describe the shape of the distribution of birth weight and
why? (2 marks)
c. What is the probability that a child chosen at random from this NHIS sub-sample will have a
birth weight in the normal range defined as weight between 2500 grams and 4500 grams?
(1 mark)
d. What is the probability that a child chosen at random from this NHIS sub-sample will have
birth weight above the normal range? Normal range is defined as weight between 2500
grams and 4500 grams. (1 mark)
——————————————————————————–
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 18 of 19
Title: ExamP1-Set33-Q01a
33. A research project investigates the association between being a smoker and cardiovascular disease
(CVD). The following stata output gives the odds ratio for being a smoker for CVD cases compared to
controls. (5 marks)
a. Is this odds ratio statistically significantly different to 1? What do you conclude? (2 marks)
b. Suppose we wish to test for a difference in the proportion of people who smoke between Victoria
and New South Wales. One way is to construct a two-way table with the counts of people who
smoke and who do not smoke in each State and do a chi square test. Name ONE other way to test
this difference (1 mark).
c. When would we use it instead of the chi square test? (2 marks)
——————————————————————————–
HSH746/946 Biostatistcs 1 Trimester 1, 2020
AT3
Page 19 of 19
Approximate price: $22
We value our customers and so we ensure that what we do is 100% original..

With us you are guaranteed of quality work done by our qualified experts.Your information and everything that you do with us is kept completely confidential.You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.The Product ordered is guaranteed to be original. Orders are checked by the most advanced anti-plagiarism software in the market to assure that the Product is 100% original. The Company has a zero tolerance policy for plagiarism.The Free Revision policy is a courtesy service that the Company provides to help ensure Customer’s total satisfaction with the completed Order. To receive free revision the Company requires that the Customer provide the request within fourteen (14) days from the first completion date and within a period of thirty (30) days for dissertations.The Company is committed to protect the privacy of the Customer and it will never resell or share any of Customer’s personal information, including credit card data, with any third party. All the online transactions are processed through the secure and reliable online payment systems.By placing an order with us, you agree to the service we provide. We will endear to do all that it takes to deliver a comprehensive paper as per your requirements. We also count on your cooperation to ensure that we deliver on this mandate.