Question: A researcher desires to estimate the difference in means of two populations. To accomplish this, she takes a random sample of 81 items from the first population. The sample yields a mean of 168 with a variance of 324. A random sample of 64 items is taken from the second population yielding a mean of 158 with a variance of 625. Compute a 94% confidence interval for the difference in population means.
a) -0.27 to 14.27
b) 3.51 to 10.49
c) 1.25 to 12.75
d) 3.02 to 16.98