Approximate the mean for the following data set. Round your answer to one decimal place.

Question

Class. Frequency

0-9. 7

10-19. 10

20-29. 8

30-39. 14

40-49. 15

Answer 1

So,there are 7 values between 0 and 9. The best we can do is assume the middle, or average, which is (0 + 9)/2 = 4.5. So we have 4.5, 7 times or a total of 4.5•7 = 31.5

Do that for each class:

0-9: 4.5•7 = 31.5

10-19: 14.5•10 = 145

20-29: 24.5•8 = 196

30-39: 34.5•14 = 483

40-49: 44.5•15 = 667.5

Now, add those up: 31.5+145+196+483+667.5 = 1523

Now divide by the number of numbers. Well that would be the sum of the frequencies, so 7 + 10 + 8 + 14 + 15 = 54

So the mean (aka average) is 1523/54 = 28.2