Question

3. Researchers are interested in whether the effects of DDT poisoning in rats are less extreme in males. An SRS of 100 male rats and an independent SRS of 100 female rats are obtained. The male rats had a sample mean of 39 and a sample standard deviation of 8. The female rats had a sample mean and standard deviation of 40 and 10, respectively. Let ui represent the true mean response for the males and up represent the true mean response of the females. They test the following hypotheses: Ho: M1 = u2, H:41 <u2 The P-value for the test is A) larger than 0.10. B) between 0.10 and 0.05. C) between 0.05 and 0.01. D) below 0.01. 6. A new diet has been developed for raising beef cows. Two random samples of size nine are independently selected, and one is given the standard diet and the other is given the new diet. After 18 weeks, the weight gain was measured, and it was found that 7, = 30 with s,= 8 and 7, -26 with s = 6. Let Hy and H2 represent the mean weight gain we would observe for the entire population of beef cows when on, respectively, a new diet and a standard diet. Assume that two-sample i procedures are safe to use. A 99% confidence interval for 41 - U2 is A) 4 + 4.7 yards. B) 4 = 6.2 yards. C) 4 8.6 yards. D) 4 = 9.8 yards.

Answer 1

Respanse of male X2- Response of female ACA and X N4 Vs 2 2 62 estimate af 6,- 8, estimate at kere X-3q, X- 40 1 1 9-40 1.28 06 l00 T00 100 2 = 0.1808 We have to kind P Value fvale PCl2ly12iall) under P12I0.7808) 02177 Valle Pvauue is laae than oelo Ans

mean Confidence intenal betn two poplh 99.% LS th20 O05 (4+9(36 2 Stn2S2 Where 2 2 16 S= 1.S S,25 Now we tind the tem t. nt250.00s t Vaue pom table X 7S 2.9 21 = 2.421 X7.SX0474 10.22 9.8 419,ara yards