00:01
We know that first step in hypothesis testing is to state null and alternative hypothesis.
00:06
In order to state null and alternative hypothesis, first consider mu1 is the mean of female worker who are not union member and mu2 be the mean of female worker who are a union member.
00:22
Therefore, null hypothesis can be stated as mu1 is equal to mu2 versus alternative.
00:30
Hypothesis is mu1 is less than mu 2.
00:34
In the question it is given that x1 bar is equal to 388, x2 bar is equal to 505, n1 is equal to 1 5 -0 -0, n2 is equal to 2 ,000000, sigma 1 is equal to 30 and sigma 2 2 is equal to 35.
00:56
In order to test the null and alternative hypothesis, we use use z test, the test statistic can be obtained by the formula x1 bar minus x2 bar minus mu2 divided by square root of sigma 1 squared divided by n1 plus sigma 2 squared divided by n2.
01:19
Substitute all the necessary values in this formula that is 388 minus 505 minus 0 divided by square root of 30 square divided by 150 plus 35 squared divided by 2000, which is equals to 1 .101136, which is equals to z equal to minus 106 .25.
01:59
In order to decide whether to reject or do not reject the null hypothesis, we use p -value approach...