Researchers Are Interested in Whether the Effects of DDT Poisoning

Multiple Choice

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 of 40 and a standard deviation of 10. Let μ₁ represent the true mean response for the males and μ₂ represent the true mean response of the females. They test the following hypotheses:
H₀: μ₁ = μ₂ versus H_a: μ₁ < μ₂
The numerical value of the t statistic = .078 and the P-value = 0.22. What should we conclude?

A) Reject the null hypothesis at significance level alpha 5%
B) Fail to reject the null hypothesis at significance level alpha 5%
C) Reject the alternative hypothesis at significance level alpha 5%
D) Fail to reject the alternative hypothesis at significance level alpha 5%