Q SCI 381 Dr.Bare
Hourly Examination Four Answers
1. Ho: u >=32 Ha: u < 32 (claim)
1.b. z = (31.7 -32)/(.7/7) = -3.00
1.c. zo = -2.33
1.d. reject Ho
1.e. At the alpha = .01 level there is sufficient
evidence to reject the null hypothesis and therefore accept the group's
claim that the mean bottle fill is less than 32 oz.
The approximate P-value for this test is .0013
2.a. Ho: u >= 10 N < 10 (claim)
2.b. t = (8.5 - 10)/(2.1/sqrt(20))= -3.194
2.c. to = -1.729
2.d. reject Ho
2.e. At the alpha = .05 level there is sufficient
evidence to reject the null hypothesis and therefore accept metro's
claim that the mean waiting time is less than 10 minutes.
3.a. Ho: sigma <= 2 Ha: sigma > 2 (claim)
3.b. chi-sq = 63.691
3.c chi-sq = (40)*2.4^2/4 = 57.6
3.d. don't reject Ho
3.e. Insufficient evidence to reject the Ho at the alpha = .01 level.
There is not enough evidence to support the professor's claim.
4.a. Ho: p1 = p2 (claim) Ha: p1 not= p2
4.b. zo = +(-) 1.96
4.c. z = (.650 - .600)/.02165 = 2.31
4.d. reject Ho
4.e. At the alpha = .05 level of significance, there is sufficient evidence
to reject the claim and conclude that the percentage of men and women who
favor stricter gun control laws are significantly different.
4.f. 95% CI is: .05 +(-)1.96*.02165
We are 95% confident that this interval contains the true population
difference of the proportion of women and men who believe in stricter
gun control laws.
5.a. Ho: ud <= 0 Ha: ud > 0 (claim)
Note: d = before - after drug
5.b. to = 2.821
5.c. t = (10 -0)/(11.49/3.16228) = 2.75
5.d do not reject Ho
5.e. Insufficient evidence to reject the Ho at the alpha = .01 level.
There is not enough evidence to conclude that the drug lowers cholesterol
levels (i.e., the manufacture's claim).
If you spot any errors let me know.