It is claimed that a new diet will reduce a person's by 4.5 kilograms on the aver age in a period of 2 weeks. the weights or 7 women who followed this diet were recorded before and after a 2-week period

Test the manufacturer's claim by computing a 95% confidence interval for the mean difference in the weight. Assume the differences of the weights to be approximately normally distributed.

Ok, maybe I'm reading something wrong, but for this problem the population variances aren't known, correct? If so, I should use a T-test, right? My problem is that this question doesn't seem to indicate whether and all of the other problems I've been given in class have always made it point to mention this. Do I proceed in solving this under the assumption that the two population variances are equal or should a I solve assuming that the population variances aren't equal? Thanks

Edit:

I think I'm reading the question wrong. This isn't a difference of two means problem. It's just a regular T-test problem. Sorry, it's been a long day.