Chapter 3: Quiz Review

1. For which measure of central location will the sum of the deviations of each value from the data's average will always be zero?
A: Mode
B: Mean
C: Median
D: Geometric mean
2. What is the relationship among the mean, median and mode in a symmetric distribution?
A: They are all equal
B: The mean is always the smallest value
C: The mean is always the largest value
D: The mode is the largest value
3. Which one of the following is referred to as the population mean?
A: Statistic
B: m
C: Sample
D: None of the above
4. What is the median of 26, 30, 24, 32, 32, 31, 27 and 29?
A: 32
B: 29
5. The U.S. Department of Education reported that for the past seven years 4,033, 5,652, 6,407, 7,201, 8,719, 11,154, and 15,121 people received bachelor's degrees in computer and information sciences.  What is the arithmetic mean annual number receiving this degree?
A: About 12,240
B: About 8,327
C: About 6,217
D: About 15,962
6. The lengths of time (in minutes) several underwriters took to review applications for similar insurance coverage are: 50, 230, 52 and 57. What is the median length of time required to review an application?
A: 54.5
B: 141.0
C: 97.25
7. Which measure of central location is found by arranging the data from smallest to largest and selecting the middle value?
A: Arithmetic mean
B: Median
C: Mode
D: Geometric mean
8. A disadvantage of using an arithmetic mean to summarize a set of data is
A: The arithmetic mean sometimes has two values
B: It can be used for interval and ratio data
C: It is always different from the median
D: It can be biased by one or two extremely small or large values
9. The mean, as a measure of central location would be inappropriate for which one of the following?
A: Ages of adults at a senior citizen center
B: Incomes of lawyers
C: Number of pages in textbooks on statistics
D: Marital status of college students at a particular university
10. What is the relationship between the variance and the standard deviation?
A: Variance is the square root of the standard deviation
B: Variance is the square of the standard deviation
C: Variance is twice the standard deviation
D: No constant relationship between the variance and the standard deviation
11. A sample of the monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical distribution.  The sample mean is $150 and the standard deviation is $20.  Using the Empirical Rule, about 95 percent of the monthly food expenditures are between what two amounts?
A: $100 and $200
B: $85 and $105
C: $205 and $220
D: $110 and $190
12. 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?
A: 106.8
B: 91.4
C: 240.3
D: 42.4
13. 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)?
A: About 4
B: About 16
C: About 100
D: About 40
14. 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?
A: 6.92
B: 4.80
C: 1.96
D: 2.33
15. The distribution of a sample of the outside diameters of PVC gas pipes approximates a symmetrical, bell-shaped distribution.  The arithmetic mean is 14.0 inches, and the standard deviation is 0.1 inches.  About 68 percent of the outside diameters lie between what two amounts?
A: 13.5 and 14.5 inches
B: 13.0 and 15.0 inches
C: 13.9 and 14.1 inches
D: 13.8 and 14.2 inches
16. If the sample variance for a frequency distribution consisting of hourly wages was computed to be 10, what is the sample standard deviation?
A: $1.96
B: $4.67
C: $3.16
D: $10.00
17.  Based on the Empirical Rule, what percent of the observations will lie above the mean plus two standard  deviations?
A: 95%
B: 5%
C: 68%
D: 2.5%

Samples of the wires coming off the production line were tested for tensile strength.  The statistical results (in PSI) were:




According to the Empirical Rule, the middle 95 percent of the wires tested between approximately what two values?
A: 450 and 550
B: 460 and 540
C: 420 and 580
D: 380 and 620

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