(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
Β. 280.6
C. 277.8
D. 296.2
4
