You want to estimate the difference between two population means using a 95% confidence interval. You need to take samples that are large enough, so that the width of the interval does not exceed 0.6....

You want to estimate the difference between two population means using a 95% confidence interval. You need to take samples that are large enough, so that the width of the interval does not exceed 0.6. From prior research it is known that the standard deviation of the first population is 3.05, and the standard deviation of the second population is 2.58. You wish to take two samples (one from each population) of the same size n. What is the minimum sample size you will need (for both of the samples)? (Round the result up to the nearest integer.)