Use the chi-square goodness-of-fit to test to determine if the following observed data are normally distributed. Let = .05.What are your estimated mean and standard deviation?

Category Observed

10–under 20 ......... 6

20–under 30 .........14

30–under 40 .........29

40–under 50 .........38

50–under 60 .........25

60–under 70 .........10

70–under 80 ......... 7