Question 1:
You have been given sample data from two offices and told that the 95% confidence interval for the difference of mean in overtime hours per year is -.01 to 100. What can you say about the difference in average overtime hours for each office?
A. Overtime hours are statistically significant at alpha=.05
B. Overtime hours are not statistically significant at a 95% confidence level.
C. Overtime hours are practically significant.
D. We can't tell from the data.
Question 2:
What if I told you in Q1 above that the sample sizes were n=20 and n=30 for each office, what would you say then?
A. A sample size of 30 is the minimum sample size to make the law of large numbers work, so we cannot draw conclusions from this data.
B. Use a t-score for the smaller sample and a z-score for the larger one.
C. If the sample sizes were increased, we would likely see a statistically significant difference at the 95% confidence level.
D. A and C
E. B and C
Question 3:
You have conducted a pilot study of a new initiative to improve employee morale, using experimental design on samples of employees, and you have found that in a regression equation morale has improved by 2 points out of 10, with a p-value of .07.
What can you say about your pilot study?
A. The t-score for my regression coefficient is likely less than 2.
B. My regression coefficient does not meet standards for statistical significance, and on that basis I cannot draw firm conclusions about my innovation.
C. This is a pilot study, so I can draw some tentative conclusions about my innovation.
D. A and C.
E. All of the above.