Given two independent random samples with the following results:
n1 = 13 n2 = 13
x1 = 186 x2 = 171
s1 = 33 s2 = 23
Use this data to find the 90% confidence interval for the true difference between the population means. Assume that the population variances are equal and that the two populations are normally distributed.
Find the standard error of the sampling distribution to be used in constructing the confidence interval. Round your answer to the nearest whole number.