Question

A researcher wants to prove that there is a difference in the average life spans between men and women in Japan. Let mu1 = average life span of Japanese women and mu2 = average life span of Japanese men. A random sample of 10 women showed an average lifespan of 83 years, with a sample standard deviation of 7 years. A random sample of 10 men showed an average lifespan of 77 years, with a sample standard deviation of 6.4 years. Assume that life spans are normally distributed and that the population variances are equal. The test statistics for this problem is 2.00. If alpha = .05 and the null hypothesis is mu1 – mu2 = 0, what is your conclusion after the difference of means hypothesis test?

Group of answer choices

a. The average life span of women is 6 years longer than the average life span of men.

b None of the above.

c The difference is not statistically significant: there is not enough evidence to conclude that the average life spans are different.

d There is a statistically significant difference in average life spans for men and women.

Answer 1

Answer:-

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