Question

Part I: Two different firms design their own version of the same aptitude test, and a psychologist administers both versions to the same randomly selected subjects with the results given below. At the .05 significance, test the clam that both versions produce the same mean. Assume both populations are normal.

Test A(before)	109	118	104	127	126	99	104	108	113
Test B (After)	102	115	107	116	104	91	113	112	112

Claim:

Null Hypothesis:

Alternative Hypothesis:

Calculator Screen Name in Ti 183:

test statistics:

Pvalue/alpha conversion

decision:

Conclusion:

Part II Construct a 95% confidence interval for Ud, the mean difference of the before minus the after times. Interpret the interval in a complete sentence.

Answer 1

The difference of true means lieing between -3.138 to 11.318.