Question 1

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A research study of 15 children with a diagnosis of ADHD wish to assess whether the BMI of the children is correlated with degrees of hyperactivity in the child. The BMI of the 15 children in a study: 22, 23, 25, 24, 18, 27, 26, 29, 28, 31, 32, 28, 33, 28, 34. What is the mean BMI of the children?

Select one:

a.

27.3

b.

28.0

c.

29.0

d.

24.5

Question 2

Please match the following terms to their definitions:

Sample Standard Deviation

Answer 1

Choose...

Total Number in the Population

Answer 2

Choose...

Total Number in Sample

Answer 3

Choose...

Population Standard Deviation Answer 4

Choose...

Sample Mean Answer 5

Choose...

Population Mean Answer 6

Choose...

Question 3

A research study examined the effects of meditation on quality of sleep. Fifty individuals were asked how many nights, on average, they lost sleep at the beginning of the study. Then all fifty individuals were placed into a meditation intervention every day for three months. At the end of the three months, the same fifty individuals were asked how many sleepless nights they had on average. The mean difference between the before and after intervention groups was 5.6 nights, with a standard deviation of 5. Calculate the z, t, or chi-square test and choose the value in the answer below.

Select one:

a.

6.15

b.

7.92

c.

8.23

d.

7.21

Question 4

A study has been designed for two schools in IL to examine whether the BMI and fasting blood glucose for students in one schools is different than that for the other school. All students in each school will participate. This study is an example of what type of sampling technique?

Select one:

a.

random

b.

cluster

c.

convenience

Question 5

Gender, disease status, alive or dead . . . these are examples of what type of variable?

Select one:

a.

Continuous Variables

b.

Ordinal Variables

c.

Dichotomous Variables

d.

Categorical Variables

Question 6

A research study wishes to examine the proportion of hypertensive individuals among three different groups of exercises: marathon runners, yoga, and CrossFit. Of the 78 marathon runners, 14 are hypertensive. Of the 63 yoga practitioners, 6 are hypertensive. And there are 16 hypertensive subjects among the 54 CrossFit athletes. What is the critical value for the test statistic? (e.g. what number are you hoping to beat in order to show a significant finding)

Select one:

a.

1.96

b.

1.65

c.

5.99

d.

4.83

Question 7

A research study wishes to examine the mean resting heart rate for 16 individuals among four different groups of exercises (evenly distributed to 4 individuals per group). What is the critical value?

Select one:

a.

2.78

b.

3.97

c.

4.26

d.

3.49

Question 8

Recall in our discussion of the normal distribution the research study that examined the blood vitamin D levels of the entire US population of landscape gardeners. The intent of this large-scale and comprehensive study was to characterize fully this population of landscapers as normally distributed with a corresponding population mean and standard deviation, which were determined from the data collection of the entire population.

Suppose you are now in a different reality in which this study never took place though you are still interested in studying the average vitamin D levels of US landscapers. In other words, the underlying population mean and standard deviation are now unknown to you. Furthermore, you would like to examine if wearing tank tops instead of short sleeve shirts significantly effects vitamin D levels. To accomplish this, you propose to collect data from the landscapers at two different points in time. Specifically, the landscapers are to wear short sleeve shirts while outside working during a period of three weeks. After three weeks, you collect blood specimens and the landscapers are then to wear tank tops for the next three weeks under the same working conditions, after which you collect blood draws a second time. You obtain research funding to randomly sample 44 landscapers, collect blood samples at two different time points as described above, and send these samples to your collaborating lab in order to quantify the amount of vitamin D in the landscapers' blood. After anxiously awaiting your colleagues to complete their lab quantification protocol, they email you the following vitamin D level data as shown in the following table.

Subject Time Point 1, Shirts Vitamin D (ng/mL) Time Point 2, Tank TopsVitamin D (ng/mL)

1 30.928 41.762

2 29.500 26.537

3 32.609 37.692

4 26.922 34.610

5 38.858 28.478

6 34.523 37.325

7 33.439 28.041

8 27.562 25.875

9 37.573 33.377

10 36.449 37.270

11 25.812 40.066

12 34.144 30.245

13 30.158 32.000

14 36.791 30.382

15 31.910 32.817

16 36.461 24.709

17 32.336 36.505

18 35.375 36.949

19 22.722 28.210

20 30.735 25.210

21 25.994 25.982

22 37.998 31.979

23 37.120 32.126

24 30.174 33.434

25 35.876 36.697

26 28.778 28.343

27 36.324 33.500

28 29.082 37.389

29 28.206 34.656

30 24.216 38.829

31 30.232 30.246

32 29.098 35.122

33 40.019 26.970

34 38.238 35.248

35 32.171 32.387

36 29.789 31.018

37 35.678 35.964

38 35.077 29.709

39 28.569 33.148

40 34.370 27.897

41 34.474 37.358

42 25.193 40.229

43 29.817 37.674

44 27.914 34.942

What is the estimated 95% confidence interval (CI) of the average difference in blood vitamin D levels between short sleeve shirt and tank top attire amongst US landscapers in ng/mL?

Please note the following: 1) in practice, you as the analyst decide how to calculate the difference in vitamin D levels between time points for a given study participant, and subsequently interpret the aggregated results appropriately in the context of the data, though for the purposes of this exercise the difference is assigned for you as follows. Define the difference as the second minus the first time points, which is common practice, since the plus or minus sign of the resulting difference reflects any change over sequential time; 2) you might calculate a CI that is different from any of the multiple choice options listed below due to rounding differences, therefore select the closest match; 3) ensure you use either the large or small sample CI formula as appropriate; and 4) you may copy and paste the data into Excel to facilitate analysis.

Select one:

a.

-1.05 to 2.86 ng/mL

b.

-0.95 to 3.14 ng/mL

c.

-1.18 to 3.30 ng/mL

d.

-0.99 to 3.09 ng/mL

Question 9

A research study of 15 children with a diagnosis of ADHD wish to assess whether the BMI of the children is correlated with degrees of hyperactivity in the child. The BMI of the 15 children in a study: 22, 23, 25, 24, 18, 27, 26, 29, 28, 31, 32, 28, 33, 28, 34. What is the standard deviation of the children?

Select one:

a.

5.21

b.

3.78

c.

4.42

d.

6.03

Question 10

A grocery store carries the following items. There are two main categories of food - conventional and organic ingredients - and four food groups. The data are shown in the following table.

Food Groups

Food Categories Grains Fruits Vegetables Meat Total

Conventional 28 32 47 200 307

Organic 147 93 253 15 508

Total 175 125 300 215 815

If all of the grains, fruits, and vegetables were accidentally displayed together without a sticker or label to mark their origin, what is the probability that you select a grain, fruit, or vegetable that is conventional into your grocery basket? First compute for yourself the row (i.e., n1+, n2+), column (i.e., n+1, n+2, n+3, n+4), and overall (i.e., n++) totals, to aid in answering the question.

Question 11

All of the patients at a sleep clinic were enrolled in a study. For the control population, family members and friends of the patients were asked to participate as well. The study aims to examine whether there are differences in biometric measures between the sleep clinic patients and this control population of friends and family. This study is an example of what type of sampling technique?

Select one:

a.

random

b.

cluster

c.

convenience

Question 12

A research study examined the cholesterol levels in two groups, intervention versus placebo, to see whether consuming more salmon in the diet would make a difference on cholesterol levels. The mean cholesterol level of the 60 people in the placebo group was 240 with a SD of 20. The 60 people in the salmon consumption group had a mean cholesterol level of 210 with a SD of 21. Calculate the z, t, or chi-square test and choose the value in the answer below.

Select one:

a.

6.91

b.

7.23

c.

8.01

d.

5.38

Question 13

Please match the following types of sampling techniques to their description:

A way to select individuals for a study using computer programs or table to identify participants without a known pattern

Answer 1

Simple Random Sample

Selecting individuals for a study using a pattern (e.g. choosing every 15th person to participate)

Answer 2

Systemic Random Sample

Within a group, choosing individuals at random to participate in a study

Answer 3

Stratified Sample

Choosing individuals for a study based on ease of identification or selection (e.g. asking all of your friends and family to participate; using all cases of a disease at a specific clinic)

Answer 4

Convenience Sample

Selecting all individuals to participate until a pre-determined number has been reached (e.g. selecting the first 100 individuals to agree to participate at a street corner)

Answer 5

Quota Sample

Question 14

A grocery store carries the following items. There are two main categories of food - conventional and organic ingredients - and four food groups. The data are shown in the following table.

Food Groups

Food Categories Grains Fruits Vegetables Meat Total

Conventional 167 1 300 177 645

Organic 8 124 0 38 170

Total 175 125 300 215 815

If all of the items were accidentally displayed together without a sticker or label to mark their origin, what is the probability that you select a fruit, vegetable, or meat in your grocery basket, regardless if it's conventional or organic? First compute for yourself the row (i.e., n1+, n2+), column (i.e., n+1, n+2, n+3, n+4), and overall (i.e., n++) totals, to aid in answering the question.

Answer:

Question 15

A research study of 15 children with a diagnosis of ADHD wish to assess whether the BMI of the children is correlated with degrees of hyperactivity in the child. The BMI of the 15 children in a study: 22, 23, 25, 24, 18, 27, 26, 29, 28, 31, 32, 28, 33, 28, 34. What is the 75th quartile of BMI of the children?

Select one:

a.

28

b.

30

c.

34

d.

27

Question 16

A research study of 15 children with a diagnosis of ADHD wish to assess whether the BMI of the children is correlated with degrees of hyperactivity in the child. The BMI of the 15 children in a study: 22, 23, 25, 24, 18, 27, 26, 29, 28, 31, 32, 28, 33, 28, 34. What is the median BMI of the children?

Select one:

a.

27.3

b.

28.0

c.

29.0

d.

24.5

Question 17

Match the following ANOVA terms to their definition:

Variability between groups; difference of group means from one group to another (e.g. Group A vs. Group B vs. Group C, etc.).

Answer 1

Choose...

Degrees of Freedom for SSB

Answer 2

Choose...

The denominator for MSE

Answer 3

Choose...

F-Statistic; test to calculate the variance between groups versus within groups.

Answer 4

Choose...

Variability within a group; difference between each observation and its group mean.

Answer 5

Choose...

Question 18

A clinical trial investigating a new cholesterol-lowering medication aims to identify whether it is any more effective than the current market favorite drug. This type of study uses what kind of statistics:

Select one:

a.

Descriptive

b.

Inferential

Question 19

A research study wishes to examine the proportion of hypertensive individuals among three different groups of exercises: marathon runners, yoga, and CrossFit. Of the 78 marathon runners, 14 are hypertensive. Of the 63 yoga practitioners, 6 are hypertensive. And there are 16 hypertensive subjects among the 54 CrossFit athletes. What is the computed test statistic based on this data?

Select one:

a.

6.98

b.

7.83

c.

6.23

d.

8.75

Question 20

A research study wishes to examine the mean resting heart rate for 16 individuals among four different groups of exercises (evenly distributed to 4 individuals per group). What type of test statistic do you need to run for this type of analysis?

Select one:

a.

Chi-Square Test of Independence

b.

Chi-Square Goodness of Fit

c.

Z-test

d.

T-test

e.

F-test