Problem Solving

31. What is the range for a sample of March electric bills amounts for all-electric homes of

similar sizes (to the nearest dollar): $212, $191, $176, $129, $106, $92, $108, $109, $103, $121,

$175 and $194.

Use the following information to answer questions 32-34.

32. The ages of a sample of the typewriters used by the typists in the typing pool were organized

into the following table.

Ages (in years) Number

2 up to 5 2

5 up to 8 5

8 up to 11 10

11 up to 14 4

14 up to 17 2

What is the range of the age (in years)?

33. What is the sample variance?

34. What is the sample standard deviation?

35. The weights of a sample of crates ready for shipment to Laos are (in kilograms): 103, 97, 101,

106 and 103. What is the mean deviation?

36. The ages of all the patients in the isolation ward of the hospital are 38, 26, 13, 41 and 22.

What is the population variance?

37. A population consists of all the weights of all defensive tackles on Sociable University's

football team. They are: Johnson, 204 pounds; Patrick, 215 pounds; Junior, 207 pounds;

Kendron, 212 pounds; Nicko, 214 pounds; and Cochran, 208 pounds. What is the population

standard deviation (in pounds)?

38. The weights (in grams) of the contents of several small bottles are 4, 2, 5, 4, 5, 2 and 6. What

is the sample variance?

39. Each person who applies for an assembly job at Robert's Electronics is given a mechanical

aptitude test. One part of the test involves assembling a plug-in unit based on numbered

instructions. A sample of the length of time it took 42 persons to assemble the unit was

organized into the following frequency distribution.

What is the standard deviation (in minutes)?

40. If the sample variance for a frequency distribution consisting of hourly wages was computed

to be 10, what is the sample standard deviation?