5. Suppose you have been asked by the CSU alumni association to compare the mean earnings of Colorado State University graduates to University of Northern Colorado graduates. You conduct a Survey using a random sample of CSU and UNC alumni: Ofthe 60 UNC alumni surveyed, their average weekly earnings are $1,300/week (standard deviation = $400). Ofthe 50 University of CSU alumni surveyed, their average weekly earnings are $1,600/week (standard deviation = $500). Your research hypothesis is that there is a difference in the earnings of CSU and UNC alumni. Answer the questions below. a. What is the null hypothesis? b. What is the standard error of the sampling distribution of the difference between the means? Calculate the zstatistic for the difference in means. Based on the z-statistic you calculated in part c, can you conclude there is difference in earnings between Colorado State University and University of Colorado alumni at the p