Complete the analysis begun in Exercise 2.
a) What is the difference in the proportions of the two types of companies?
b) What is the value of the z-statistic?
c) What do you conclude at α = 0.05?

Data From Exercise 2

Do people who work for non-profit organizations differ from those who work at for-profit companies when it comes to personal job satisfaction? Separate random samples were collected by a polling agency to investigate the difference. Data collected from 422 employees at non-profit organizations revealed that 377 of them were “highly satisfied.” From the for-profit companies, 431out 518 employees reported the same level of satisfaction. Find the standard error of the difference in sample proportions.