(Choose 1 answer)
A retail store executive wants to know whether the store's average Internet sales exceed its average mail-order sales. A random sample of 15 Internet sales yielded a mean sale amount of $86.40 with a standard deviation of $18.75. A random sample of 10 mail-order sales yielded a mean sale amount of $75.20 with a standard deviation of $14.25. Assume the population variances are equal and the two populations from which the samples are drawn are normally distributed. What is the pooled variance ?
Α. 293.5
B. 280.6
C. 277.8
D. 296.2
