Texas Instruments TINSPIRE Teacher Software Guidebook - Page 596

This test is useful in determining if the difference between a sample mean and a population mean is statistically significant when you know the true deviation for a population. t test (tTest) performs a hypothesis test for a single unknown population mean, m, when the population standard deviation, s, is unknown. It tests the null hypothesis H0: m=m0 against one of the alternatives below. • Ha: mƒm0 • Ha: mm0 This test is similar to a z-test, but is used when the population is small and normally distributed. This test is used more frequently than is the z-test because small sample populations are more frequently encountered in statistics than are large populations. This test is useful in determining if two normally distributed populations have equal means, or when you need to determine if a sample mean differs from a population mean significantly and the population standard deviation is unknown. 2-Sample z Test (zTest_2Samp) tests the equality of the means of two populations (m1 and m2) based on independent samples when both population standard deviations (s1 and s2) are known. The null hypothesis H0: m1=m2 is tested against one of the alternatives below. • Ha: m1ƒm2 • Ha: m1m2 2-Sample t Test (tTest_2Samp) tests the equality of the means of two populations (m1 and m2) based on independent samples when neither population standard deviation (s1 or s2) is known. The null hypothesis H0: m1=m2 is tested against one of the alternatives below. • Ha: m1ƒm2 • Ha: m1m2 584 Using Lists & Spreadsheet