Q1) Table illustrates the SAT verbal test scores for 9 randomly selected female students and 14 randomly selected male students. Suppose that sat verbal test scores are normally distributed. At a = 0.01, test claim that test score variance for females is different from that for males.
|
Female
|
480
|
610
|
340
|
630
|
520
|
690
|
540
|
|
Male
|
560
|
680
|
360
|
530
|
380
|
460
|
630
|
|
Female
|
600
|
800
|
|
|
|
|
|
|
Male
|
310
|
730
|
740
|
520
|
560
|
400
|
510
|
Q2) Steel pipe fittings company claims that yield strength of its nontempered couplings is more variable than that of its tempered couplings. Random sample of 9 tempered couplings has standard deviation of 13.1 megapascals, and similar sample of 9 nontempered couplings has standard deviation of 25.4 megapascals. From past data, it is recognized that company's production process results in normally distributed yield strengths. Test company's claim at a = 0.05.