Question

*Please don't copy other experts' solutions

A) Suppose that you randomly select a sample of 40 part-time journalists in January, and find that the sample pay per hour is £20.10 and the sample SD is £3.15. Compute a 95% confidence interval for the mean hourly pay of all of the part-time journalists in January, and then provide an interpretation of your interval.


B) Suppose that part-time journalists earn £17.84 per hour on average in July. Test if the data collected in Part A) suggest that the part-time journalists in January earn, on average, more than those working as part-time journalists in July. Do a hypothesis test given a 10% significance level to answer this, and then provide a conclusion.

Answer 1

In option A) reprenets the mean of pay per hour of all journalists in january

in option B) t represents t distribution and n-1 represents the degree of freedom

CI stands for confidence interval

Conclusion of option B : We have sufficient evidence to reject the true hypothesis at 10%level of significance and therefore we can say that part time journalist in january earn more than part time journalist in july