In this case, we want to test whether the average salary of a person who has been to school for less than 16 years in less than that of another who spend more than 16 years in school.
In hypothesis testing, there is the null hypothesis and the alternative hypothesis. The null hypothesis is the assumed truth while the alternative is what the researcher/analyst will settle for if the assumed truth (null hypothesis) if found to be false. The hypothesis is below.
A sample is used instead of using the whole population to draw inferences about the population since it is cheap, it takes a shorter while and has scope like a complete observation of the whole population. In this case, the People who spend less than 16 years in education were 79 while those who had spend more than 16 years in education were 21. Thus, a total of 100 were selected for this study. The people who spend less than 16 years are denoted by 1 while those who spend more than 16 years are denoted by 2.
This is a single tailed test to the left, the average salary for those who have been in education for less than 16 years is 26,998.68 with a standard deviation of 13,305.31. The average salary for those who have been in education for more than 16 years is 45,259.52 with a standard deviation of 21,322.18.
For those who spent less than 16 years, the salary range was 72,604 with a minimum of 10,997 and a maximum of 83,601 while those with more than 16 years, the range was 73,690 and a minimum of 9,879 and a maximum of 83,569. The maximum and minimum of both less than and more than 16 years are almost he same.
From the above results, it is evident that the calculated value for Z lies in the critical region; is not in the acceptance region but in the rejection region as shown above. The null hypothesis is rejected and the alternative accepted.
We conclude that, the average salary for those who have been in education for less than 16 years is less than the