Random Samples of 5 Japanese Women and 10 Japanese Men $\mu$

Random samples of 5 Japanese women and 10 Japanese men showed an average life span of 83 years for the women and 77 years for the men. The standard deviation was 2 years for the women and 1 year for the men. Calculate a 95% confidence interval for the difference in average life spans (women $\mu$ men). Assume that the life spans are normally distributed, but do not assume the population variances are equal, and use the conservative "by-hand" estimate for the degrees of freedom.