In past years at least 20% of the students at State U. chose to pursue public service careers after graduation. For an editorial piece on declining student commitment to public service, the school newspaper surveyed a simple random sample of 100 currently enrolled students and found that only 12 of them expressed an interest in a career in public service. Does this sample result provide statistical evidence of a decline in student commitment for the population of students currently enrolled at State U? That is, can the sample result be used to reject a .20 null hypothesis? Use a significance level of 5%. 

a. Show the null and alternative hypotheses.

b. Based on the sample result, should you reject the null hypothesis? Explain.