A teacher randomly selects ten students to participate in a week of training designed to improve their typing speed. The teacher times their speed before and after the course, to see if the course is worth the time and expense. State the appropriate null and alternative hypothesis and conduct test of hypothesis at 0.05 level of significance. Also find 95% C.I for the paired population mean.

After Course

61

52

45

47

57

71

58

Before Course

63

58

35

46

52

60

49