1) A researcher records the number of classroom interruptions during each of two class sessions. Which session has the smallest standard deviation?

Session A: 12, 15, 18, 24, and 30 Session B: 8, 10, 12, 16, and 20

a) Sample A

b) Sample B

c) Both Samples have the same standard deviation.

d) none of the above

2) Which of the following distributions has the largest variability?

a) scores: 1, 3, 6, 9, and 12

b) scores: 22, 24, 26, 28, and 30

c) scores: 2, 3, 4, 5, and 6

d) scores: 1, 2, 3, 4, and 5

3) A researcher records the following data for the time (in seconds) it takes five rats to cross an electrical grid to obtain reinforcement on the other side: 12, 9, 13, 4, and 12. Is the mean equal to the mode in this example?

a) Yes.

b) No; the mode is larger than the mean.

c) No; the mean is larger than the mode.

d) There is not enough information to answer this question.