A-3

T test Versus Z test

Conduct a T-test between the difference between the mean extrinsic score of male and female employees at 0 .5 significance level

Null hypothesis : There is no difference between the mean extrinsic score of male and female employees

Alternative : The difference between the mean extrinsic score of male and female employees is greater than zero

Alpha level (a 0 .05

Degrees of freedom (df (n1 n2 - 2 (14 11 - 2 23

Tcritical (1-tailed at 0 .05 a and 23 df 1 .7

Decision Rule , reject null

hypothesis if Tobserved Tcritical

Tobserved -1 .1

Since Tobserved (-1 .1 Tcritical (1 .7 , we fail to reject the null hypothesis

We are 95 confident that there is no difference between the mean extrinsic score of male and female employees

Z-tests are used whenever the population parameter is present . For example , one can use z-test in a population where the mean is already known . T-tests are used whenever the parameter of concern is not present or is not known . For example , the population mean is not present , and then one can use t-test to infer something about the population through samples (Climent , 2009

Samples are used instead of population because of some difficulties First is that population is difficult to be measured . This is because a population can be so big that it is impossible to get data out of it Second is time constraints , it is time consuming to measure a population that is so big . Third are financial...