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 age of onset of a certain disease for men and women who get the disease. Let $µ_1$ = average age of onset for women and $µ_2$ = average age of onset for men. A random sample of 30 women with the disease showed an average age of onset of 83 years, with a sample standard deviation of 11.5 years. A random sample of 20 men with the disease showed an average age of onset of 77 years, with a sample standard deviation of 4.5 years. Assume that ages at onset of this disease are normally distributed for each gender, do not assume the population variances are equal, and use the conservative "by hand" estimate for the degrees of freedom.
-Which of the following is an appropriate conclusion?

A) There is a statistically significant difference in average age at onset for men and women.
B) The difference is not statistically significant: there is not enough evidence to conclude the average ages at onset are different.
C) The average age at onset for women is 6 years later than the average age at onset for men.
D) None of the above.