At Lakeview High School, students either walk to school or provide their own transportation. Suppose that those who walk have a mean commute time of 121212 minutes with a standard deviation of 555 minutes, while those who use some other form of travel have a mean and standard deviation of 161616 and 666 minutes, respectively. The principal takes an SRS of 505050 students who walk, and an independent SRS of 303030 students who use some other form of travel. The principle calculates the mean commute time for each sample, then looks at the difference (\text{Other}-\text{Walk})(Other−Wa lk)left parenthesis, start text, O, t, h, e, r, end text, minus, start text, W, a, l, k, end text, right parenthesis between the sample means.