Thank you for the opportunity to help you with your question!
H0 : mean after the course is equal to the mean before the course
H1 : Mean after course is greater than the mean before the course
since the data is collected from the same group of salespeople we use a paired t-test for the means.
using excel the following results were obtained
t-Test: Paired Two Sample for Means
Hypothesized Mean Difference
t Critical one-tail
t Critical two-tail
our test is one tailed hence since P-value is greater than 0.05 at one-tailed level of significance we do not reject the null hypothesis and conclude that the mean weekly sales does not increase as a result of attending the course.Please let me know if you need any clarification. I'm always happy to answer your questions.
Pearson correlation measures the relationship between two variable. For this case it indicates that there exists a strong positive relationship between the two variables. However, this should not worry since the data is paired and we are not interested in the relationship of the two.