The coach of an adult Masters Swim class selected eight swim

The coach of an adult Master\'s Swim class selected eight swimmers within each of the two age groups shown below. A 50-yard freestyle time is recorded for each swimmer. The resulting times (seconds) are shown below. Which statistical test would you choose to compare the two groups?

a. t-test for independent samples with known variances

b. z-test for two independent proportions

c. t-test for independent samples with unknown variances

d. t-test for paired samples

Solution

Since population variances are unknown and sample sizes are small. Also samples are independent. We must use:

c. t-test for independent samples with unknown variances