A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken.

You are given the following results.

1) The standard deviation of the difference between the means of the two populations is

a) 12.9

B) 9.3

C) 4

D) 2

2) The 95% confidence interval for the difference between the two pop. Means is

A) -9.92 to -2.08

B)-3.92 to 3.92

C) -13.84 to 1.84

D) -24.228 to 12.23

3) The test statistic for the difference between the two pop. means is

A) -0.47

B) -0.65

C) -1.5

D) -3.0

4) The p-value for the difference between the two pop. means is

A) 0.0014

B) 0.0028

C) 0.4986

D) 0.9972

5) What is the conclusion that can be reached about the difference in the average final examination scores between the two classes? (Use a .05 level of significance)

A) There is a statistically significant difference in the average final examination scores between the two classes.

B)There is no statistically significant difference in the average final examination scores between the two classes.

C) It is impossible to make a decision on the basis of the information given

D) There is a difference, but it is not significant.

Transcribed Image Text:

Today 82 Mean Variance Sample Size 45 112.5 5 Years Ago 88 54 36 Today 82 Mean Variance Sample Size 45 112.5 5 Years Ago 88 54 36

Answer rating: 100% (QA)

1 Substitute 45 for n 1 36 for n 2 1125 for S 1 2 and 54 for S 2 2 82 in standard deviation formula D 2 The standard deviation of the difference betwe... View the full answer