Use the Following Information for Questions

Multiple Choice

Use the following information for questions:
For a randomly selected sample of 20 new mothers in the year 2000, the mean age was 24.6 years. For a randomly selected sample of 10 new mothers in 1970, the mean age was 21.4 years. The difference between the mean ages is 3.2 years, and the standard error of the difference is 1.366. Assume that the ages of new mothers are normally distributed, do not assume the population variances are equal, and use the conservative "by hand" estimate for the degrees of freedom.
-Calculate a 90% confidence interval for the difference in population mean ages of new mothers in the two years (year 2000 - year 1970) .

A) (0.84, 5.56)
B) (0.78, 5.67)
C) (0.70, 5.70)
D) None of the above