(Two-Sample t-Test Assuming Unequal Variances)

1. Refer to Example 10.25. If the ratio of the two sample variances had been so large that you could not assume equal variances (we use “greater than 3” as a rule of thumb), you should use stat ➤ TESTS ➤ 4:2-SampTTest but select “No” on the line marked

“Pooled.” A portion of the results are shown in Figure 10.30(b).

2. You will see slight differences in the value of the test statistic, the degrees of freedom, and the p-value, but the conclusions did not change.

3. In Section 10.6, we presented a formal test of hypothesis for the equality of two variances using the F-test. Use stat ➤ TESTS ➤ E:2-SampFTest and select Data in the

“Inpt:” line. Make sure that lists L1 and L2 are selected and that the alternative hypothesis is  ? 1 2. A portion of the output, shown in Figure 10.31 shows the test statistic, F 51.27 with p-value50.740. There is no significant difference in the two variances

Transcribed Image Text:

NORMAL FLOAT AUTO REAL RADIAN MP 01702 2-Samp Test F=1.268881943 P=0.7401185434 Sx1 9.913014534 Sx2=8.800252522 X1-81.625 X2 81.77777778 n1=8 0