What is pooled variance?
a. The weighted average of the two sample variances.
b. The variance of the difference between the sample means.
c. The sum of the two sample variances.
d. The variance of the populations from which the samples were drawn.
Question 2
Suppose you tested two age groups on the number of details they could recall from a paragraph. The mean for the older group is 16, and the mean for the younger group is 14 . Further suppose that you fail to reject the null hypothesis for this independent samples t-test. Which of the following best accounts for the difference between these sample means?
a. A math error has been made somewhere.
b. The null hypothesis was incorrect to start with.
c. The sample means probably came from different populations, and the difference is due to sampling error.
d. The sample means probably came from the same population, and the difference is due to sampling error.
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