Question 1
3.125 out of 3.125 points
Correct
For a linear regression b1 is the estimated y-intercept, and b0
is the estimated slope of the regression line.

Question 2
3.125 out of 3.125 points
Correct
The decision rule for a Wilcoxon signed-rank test is always to reject H0 if W is greater than or equal to
the critical value.

Question 3
3.125 out of 3.125 points
Correct
Hypothesis testing on samples with fewer than 30 participants can be carried out by using the t-value for
the corresponding level of significance in place of the z
value when setting up the decision rule.

Question 4

3.125 out of 3.125 points
Correct
The Cochran–Mantel–Haenszel method is a technique that generates an estimate of an association
between a risk factor or exposure and an outcome accounting for confounding.

Question 5
3.125 out of 3.125 points
Correct
Type I error occurs when H0 is correct but H0 is rejected.

Question 6
0 out of 3.125 points
Incorrect
The degrees of freedom in a chi-squared test equal to the number of participants in the test minus 1.

Question 7
0 out of 3.125 points
Incorrect

The test statistic for a Wilcoxon signed-rank test is always the smaller of the number of the total number
of positive or negative signs.

Question 8
3.125 out of 3.125 points
Correct
The sample correlation coefficient is equal to the covariance of x and y
divided by the square root of the product of sx2 times sy2.

Question 9
3.125 out of 3.125 points
Correct
A clinical trial was conducted comparing a new compound designed to improve wound healing in trauma
patients to a placebo. After treatment for 5 days, 58% of the patients taking the new compound had a
substantial reduction in the size of their wound as compared to 44% in the placebo group. The number
of subjects would be required to detect the difference in proportions observed in the trial with 80%
power at α = 0.05 in a two sided test is 200 in each group.

Question 10
3.125 out of 3.125 points
Correct

A Kruskal-Wallis test is used to compare a continuous outcome in matched samples where there are
greater than two matches.