Chapter 3 - Data Description



Chapter 3 Review

Multiple choice

1. What is the median of the following set of values?

9, 7, 4, 2, 13

A) 4 B) 6 C) 7 D) 8

2. Find the mode for the following data?

5, 4, 3, 4, 5, 6, 5, 5, 3, 4

A) 3 B) 4 C) 5 D) 6

3. Find the mean of the following data set?

9, 4, 7, 2, 13

A) 4.0 B) 6.0 C) 7.0 D) 8.0

4. What is the median of the following set of values?

6, 20, 18, 14, 18, 13, 14, 18

A) 12 B) 16 C) 14 D) 18

5. Determine the range for the following data set.

4, 7, 3, 16, 5, 22, 8

A) 4 B) 3 C) 14 D) 19

6. What is the midrange of the following data set?

1, 7, 6, 8, 0, 8, 14, 14, 14

A) 7 B) 8 C) 1 D) 14

7. Which score has the highest relative position?

a. X = 12 [pic] s = 4

b. X = 170 [pic] s = 32

c. X = 180 [pic] s = 8

d.

8. If a set of data has 49 values with a variance of 4.4, then the standard deviation is _________.

A) 0.6 B) 0.3 C) 0.1 D) 2.1

9. If a student scored 82 points on a test where the mean score was 78.2 and the standard deviation was 3.7. The student's z score is _______.

A) 21.14 B) 22.16 C) 0.28 D) 1.03

True/False

10. If a distribution is negatively skewed as shown in the figure below, the mean will fall to the right of the median and the mode will fall to the left of the median.

[pic]

11. The median can be a more appropriate measure of central tendency if the distribution of the data is extremely skewed.

12. The variance of a data set is the square root of the standard deviation.

13. The range of a data set is the difference between the highest value and the lowest value.

14. Chebyshev's theorem can be used to find the minimum percentage of the values in a data set that will fall within a certain distance of the mean.

15. The coefficient of variation for a data set is the mean divided by the standard deviation, expressed as a percentage.

16. The interquartile range IQR is found by subtracting the mean from the maximum value of a data set.

17. The percentile corresponding to a given data value X is computed by adding the 0.5 to number of values less than X then dividing by the total number of values in the data set.

18. For a set of data with a mean of 24 and a variance of 36, approximately 68% of the values will fall between 18 to 30.

19. A five-number summary of a data set consists of the minimum, [pic] , the median, [pic] , and the maximum.

Fill in the blank

20. A ______________ is the midpoint in a data array.

21. The _______________and ______________ are two measures of variation used to describe the spread of the data in a data set.

22. ______________ divide a distribution into four groups, and __________divide a distribution into ten groups.

23. A characteristic or measure obtained by using all the data values for a specific population is called a _____________.

24. A characteristic or measure obtained by using all the data values for a specific sample is called a ____________.

25. Q2 = P___ = D____

26. Q1 = P_____

27. Q3 = P ____

Calculations

28. In an advertisement, a retail store stated that its employees averaged 9 years of service. The dsitrbution is shown here.

Number of employees Years of service

8 2

2 6

3 10

Using the weighted mean, calculate the correct average.

29. The average number of newspapers for sale in an airport newsstand is 12, and the standard deviation is 4. The average age of the pilots is 37 years, with a standard deivation of 6 years. Which data set is more variable?

30. Shown here is a frequency distribution for the number of inches of rain received in 1 year in 25 selected cities in the United States.

Number of inches Frequency

5.5-20.5 2

20.5-35.5 3

35.5-50.5 8

50.5-65.5 6

65.5-80.5 3

80.5-95.5 3

Find each of these.

a. Mean

b. Modal class

c. Variance

d. Standard deviation

31. Find the weighted mean for a particular student’s scores on three exams if the first on was worth 75 points and the student received a score of 70%. The second was worth 50 points and the student received a score of 80%, and the third was worth 30 points and the student received a score of 95%.

32. Draw a sketch of a boxplot that is negatively skewed.

33. The following data lists the number of children who attend an after-school program over an 11-day period.

20 22 29 37 49 56 64 70 70 87 92

Find the:

a. Mean

b. Median

c. Mode

d. Midrange

e. Range

f. Variance

g. Standard Deviation

h. Use Chebyshev’s theorem to find the range in which at least 75% of the data values will fall.

i. Find the percentile rank of 87.

j. Which value corresponds to the 30th percentile?

k. Make a (modified) boxplot and comment on its shape.

34. The number of home runs hit by the leaders in the National League during the 2001 MLB seasons had a mean of 37.9 and a standard deviation of 11. Find the minimum percentage of data values that will fall within the range of 15.9 and 59.9 home runs. Use Chebyshev’s Theorem.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download