A coffee shop franchise owner is looking at two possible locations for a new shop. To help him decide, he looks at the number of pedestrians that go by each of the two locations in one-hour segments. At location A, counts are taken for 35 one-hour units, with a mean number of pedestrians of 421 and a sample standard deviation of 122. At the second location (B), counts are taken for 50 one-hour units, with a mean number of pedestrians of 347 and a sample standard deviation of 85. Assume the two population variances are not known but are equal. Calculate a 95 percent confidence interval for the difference in pedestrian traffic at the two locations.