Question

1.

Researchers measured skulls from different time periods in an attempt to determine whether interbreeding of cultures occurred. Results are given below. Assume that both samples are independent simple random samples from populations having normal distributions. Use a

0.050.05

significance level to test the claim that the variation of maximal skull breadths in 4000 B.C. is the same as the variation in A.D. 150.

	n	x overbarx	s
4000 B.C.	3030	131.01131.01 mm	5.135.13 mm
A.D. 150	3030	136.42136.42 mm	5.385.38 mm

Identify the test statistic.

​(Round to two decimal places as​ needed.)

Use technology to identify the​ P-valu

2.

Words were displayed on a computer screen with background colors of red and blue. Results from scores on a test of word recall are given below. Use a

0.050.05

significance level to test the claim that the samples are from populations with the same standard deviation. Assume that both samples are independent simple random samples from populations having normal distributions. Does the background color appear to have an effect on the variation of word recall​ scores?

	n	x overbarx	s
Red Background	3535	15.3215.32	5.915.91
Blue Background	3636	12.0912.09	5.495.49

Identify the test statistic.

​(Round to two decimal places as​ needed.)

Use technology to identify the​ P-valu

3.

The accompanying table gives results from a study of words spoken in a day by men and women. Assume that both samples are independent simple random samples from populations having normal distributions. Use a

0.050.05

significance level to test the claim that the numbers of words spoken in a day by men vary more than the numbers of words spoken in a day by women.

	n	x overbarx	s
Men	187187	15 comma 667.615,667.6	8 comma 632.38,632.3
Women	208208	16 comma 215.716,215.7	7 comma 301.37,301.3

Identify the test statistic.

​(Round to two decimal places as​ needed.)

Use technology to identify the​ P-valu

Answer 1