Use the Following Information for Questions:
a Researcher Wants $µ_1$

Multiple Choice

Use the following information for questions:
A researcher wants to assess if there is a difference in the average life spans between men and women in Japan. Let $µ_1$ = average life span of Japanese women and $µ_2$ = 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.
-Which of the following is an appropriate conclusion?

A) There is a statistically significant difference in average life span between men and women.
B) The difference is not statistically significant so there is not enough evidence to conclude that the life spans are different.
C) The average life span of women is 6 years longer than the average life span of men.
D) None of the above.