Statistics Multiple Choice

The following True/False, Multiple Choice, and Fill-in-the-Blank Questions are taken from the material covered in Weeks 1-3. Please post your answers in the Assignments newsgroup no later than Day 6, Tuesday, of Week 4.

True/False

T F 1. Roman letters usually represent population parameters, whereas Greek letters usually represent statistics.

T F 2. Although several statistics may be available, the nature of the problem you are trying to solve indicates the choice of which statistic to use.

T F 3. The most common measure of the center value of a set of data is the sample mean.

T F 4. The sample mean is calculated by adding up all the values in the sample and then dividing the sum by the square root of the sample size.

T F 5. When several data values are far from the majority of the values in a sample, the sample mean will compensate for the extreme cases by moving further away from the extremes and closer to the majority.

T F 6. The sample mean not only measures the central value of the sample data, it also indicates the number of observations that are above and below it.

T F 7. The sample median measures the middle value of the sample, but it can be found only after the data has been sorted in numerical order.

T F 8. If one sample of ordered data contains 25 observations and another contains 26, the median of both samples is the 13th observation.

T F 9. To approximate the number of classes when developing a frequency table for measurement data, simply divide the size of the population by the sample size or use ten classes, whichever is the smaller.

T F 10. The recommended size (width) of the class interval in a frequency table for measurement data can be found by taking the difference between the maximum and minimum value of the data and dividing that amount by the number of classes.

T F 11. There is little, if any, reason to understand how to create bar charts because computer software will create them for you once the data have been entered into a spreadsheet.

T F 12. If a bar chart contains an "other" category that contains values not included in the other categories, it can safely be removed from the chart.

Fill-in-the-Blank

13. A collection of data representing the weights of the last 64 customers at an "all you can eat" restaurant contained values that ranged between a low of 115.5 pounds to a high of 275.5 pounds. The most appropriate frequency table describing the weights of the customers should have ___________ classes with an interval of ___________ pounds in each class.

14. A _____________ chart portrays the frequency or relative frequency from a table in the form of a horizontal or vertical rectangle.

15. A _____________ diagram is a bar chart in which categories are plotted in order of decreasing relative frequency and in which the cumulative relative frequency is plotted on the same graph.

16. The principle that, in most cases, 80% of the observations fall into only 20% of the categories is called the ______________.

17. When a pie chart is constructed, each slice of the pie represents a _____________, and the size of the slice is proportional to the relative frequency of the ______________.

Multiple Choice

Consider the following information for questions 18 - 21.
Doug Larch, the manager of a popular local barbershop, has decided to evaluate the time required by his customers to obtain a haircut, pay, and depart. Doug borrowed the clock punch from one of the offices in the shopping center and asked the next 36 customers to punch in when they arrived at his shop and punch out after paying for their haircut. The following data was obtained (in minutes):
23 36 41 33 24 19 17 40 32
32 25 28 46 31 22 24 51 19
15 39 42 53 20 19 26 39 43
27 33 44 28 21 37 52 45 27
Doug chose the following classes for the data, (left end point excluded, right end point included):
14 - 21
21 - 28
28 - 35
35 - 42
42 - 49
49 - 56

18. Doug's frequency table contains ___________ class intervals.
a. 3
b. 4
c. 5
d. 6

19. The width of each class interval in Doug's frequency table is ___________ minutes.
a. 4
b. 5
c. 6
d. 7

20. How many customers are contained in the lowest (shortest time) class interval?
a. 7
b. 6
c. 5
d. 4

21. The class interval containing the most customers is
a. 14 - 21 minutes.
b. 21 - 28 minutes.
c. 28 - 35 minutes.
d. 35 - 42 minutes.

Use the following information for questions 22 - 26:

Shown below is a pie chart of responses from 200 small business owners to the question "What is the most important technological factor affecting your business in the past year"?

22. What technological factor had the highest frequency of occurrence?
a. e-mail
b. Internet
c. cell phones
d. fax machines

23. What is the size of the angle corresponding to the slice of the pie chart that represents the Internet?
a. 135
b. 145
c. 153
d. 160

24. What is the size of the angle corresponding to the slice of the pie chart that represents Fax machines?
a. 30
b. 45
c. 60
d. 75

25. What pair of technological factors had the highest frequency of occurrence?
a. cell phones and Internet
b. e-mail and fax machines
c. cell phones and fax machines
d. Internet and fax machines

26. Which of the five slices of the pie chart is the middle one as measured by its size?
a. Internet
b. cell phones
c. fax machines
d. e-mail