1. Ten randomly selected people took an IQ test A, and next day they took a very similar IQ test B. Their scores are shown in the table below.

Person	A	B	C	D	E	F	G	H	I	J
Test A	116	103	104	112	88	74	99	85	94	119
Test B	116	105	109	117	86	74	103	87	96	122

1) Construct a95% confidence interval for the mean of the differences. Again, use (Test A - Test B). ______<<______

2. Never forget that even small effects can be statistically significant if the samples are large. To illustrate this fact, consider a sample of 145 small businesses. During a three-year period, 14 of the 100 headed by men and 8 of the 45 headed by women failed.

(c) It is wise to use a confidence interval to estimate the size of an effect rather than just giving a P-value. Give 95% confidence intervals for the difference between proportions of men's and women's businesses (men minus women) that fail for the settings of both (a) and (b). (Be sure to check that the conditions are met. If the conditions aren't met for one of the intervals, use the same type of interval for both) Interval for smaller samples:____to_____ Interval for larger samples:_____to______

3.

A study was conducted to determine whether the final grade of a student in an introductory psychology course is linearly related to his or her performance on the verbal ability test administered before college entrance. The verbal scores and final grades for10students are shown in the table below.

Student	Verbal Scorex	Final Gradey
1	74	64
2	29	95
3	39	84
4	36	93
5	57	83
6	54	100
7	48	68
8	80	93
9	68	91
10	29	89

Calculate the residual for the tenth student:_____