Question

The test-retest method is one way of establishing the reliability of a test. The test is administered, and then, at a later date, the same test is re-administered to the same individuals. The correlation coefficient is computed between the two sets of scores. The following test scores were obtained in a test-retest situation. (Give your answers correct to two decimal places.)

First Score	84	73	98	92	86	69	93	66	89	97
Second Score	74	92	56	57	80	90	73	65	60	81

(a) Find r.


(b) Set a 95% confidence interval for ρ.

Lower Limit	_____
Upper Limit	_____

You may need to use the appropriate table in Appendix B to answer this question.

Answer 1