A marketing study was conducted to compare the mean age of male and female purchasers of a certain product. Random and independent samples were selected for both male and female
Purchasers of the product. It was desired to test to determine if the mean age of all female
Purchasers exceeds the mean age of all male purchasers. The sample data is shown here:
Female: n = 10, sample mean = 50.30, sample standard deviation = 13.215
Male: n = 10, sample mean = 39.80, sample standard deviation = 10.040
Which of the following assumptions must be true in order for the pooled test of hypothesis to be
Valid?
I. Both the male and female populations of ages must possess approximately normal probability
Distributions.
II. Both the male and female populations of ages must possess population variances that are
Equal.
III. Both samples of ages must have been randomly and independently selected from their
Respective populations.
A)I only
B)I, II, and III
C)II only
D)III only

Question

Quizplus · Accepted Answer

For a pooled test of hypothesis to be valid, it is necessary that: I. Both populations are approximately normally distributed, especially important when sample sizes are small. II. The population variances are equal, as the pooled test assumes homogeneity of variances. III. The samples are randomly and independently selected to ensure the validity of statistical inference.

A Marketing Study Was Conducted to Compare the Mean Age