Stats Ch 2 Multiple Choice

Scatter plots

shape of supply curve= strong positive=spread out = weak positive shape of demand curve= strong negative = spread out = weak negative.

Exhibit 2-1 The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 - 9 20 10 - 19 80 20 - 29 200 30 - 39 100 8) Refer to Exhibit 2-1. The percentage of students working 19 hours or less is a. 20% b. 25% c. 75% d. 80%

b. 25%

2) Qualitative data can be graphically represented by using a(n) a. histogram b. frequency polygon c. ogive d. bar graph

d. bar graph

6) A histogram is said to be skewed to the left if it has a a. longer tail to the right b. shorter tail to the right c. shorter tail to the left d. longer tail to the left

d. longer tail to the left

16 (i) A frequency distribution is grouping of data into classes showing the number of observations in each class. (ii) The midpoint of a class, which is also called a class mark, is halfway between the lower and upper limits. (iii) A class interval, which is the width of a class, can be determined by subtracting the lower limit of a class from the lower limit of the next higher class. A) (i), (ii) and (iii) are all correct statements. B) (i) and, (ii) are correct statements but not (iii). C) (i) and, (iii) are correct statements but not (ii). D) (ii) and, (iii) are correct statements but not (i). E) All statements are false.

A) (i), (ii) and (iii) are all correct statements.

18. (i) Simple bar charts may be constructed either horizontally or vertically. (ii). A frequency polygon is a very useful graphic technique when comparing two or more distributions (iii) A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values. A) (i), (ii) and (iii) are all correct statements. B) (i) and, (ii) are correct statements but not (iii). C) (i) and, (iii) are correct statements but not (ii). D) (ii) and, (iii) are correct statements but not (i). E) All statements are false.

A) (i), (ii) and (iii) are all correct statements.

14) If Gallup, Harris and other pollsters asked people to indicate their political party affiliation - Liberal, Conservative or NDP, the data gathered would be an example of which scale of measurement? (Lind) A) Nominal B) Ordinal C) Interval D) Ratio E) None of the choices are correct

A) Nominal

10). The main purpose of descriptive statistics is to: (Lind) A) Summarize data in a useful and informative manner. B) Make inferences about a population. C) Determine if the data adequately represents the population. D) Gather or collect data.

A) Summarize data in a useful and informative manner.

11) . Colleen Waite, Director of General Canadian Sales, is concerned by a downward sales trend. Specifically, their customer base is stable at 2,200, but they are purchasing less each year. She orders her staff to search for causes of the downward trend by selecting a focus group of 50 customers. (Lind) A) The focus group of 50 customers represents a sample. B) The focus group of 50 customers represents a population. C) The focus group of 50 customers represents an inferential statistic. D) The focus group of 50 customers represents a census.

A) The focus group of 50 customers represents a sample.

9). (i) There are two types of variables - quantitative and qualitative. (ii) A Qualitative variable is nonnumeric and we are usually interested in the number or percent of the observations from each category. (iii) Qualitative variables can be further divided into discrete and continuous variables. (L) A) (i), (ii) and (iii) are all correct statements. B) (i) and, (ii) are correct statements but not (iii). C) (i) and, (iii) are correct statements but not (ii). D) (ii) and, (iii) are correct statements but not (i). E) All statements are false.

B) (i) and, (ii) are correct statements but not (iii).

13). A bank asks customers to evaluate the drive-thru service as to good, average, or poor. Which level of measurement is this classification? (Lind) A) Nominal B) Ordinal C) Interval D) Ratio E) None of the choices are correct

B) Ordinal

17. (i) A frequency distribution is grouping of data into classes showing the number of observations in each class. (ii) In constructing a frequency distribution, you should try to have open-ended classes such as "Under $100" and "$1,000 and over". (iii) A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values. A) (i), (ii) and (iii) are all correct statements. B) (i) and, (ii) are correct statements but not (iii). C) (i) and, (iii) are correct statements but not (ii). D) (ii) and, (iii) are correct statements but not (i). E) All statements are false.

C) (i) and, (iii) are correct statements but not (ii).

12). What type of data is the number of robberies reported in your city? (Lind) A) Attribute B) Continuous C) Discrete D) Qualitative E) None of the choices are correct

C) Discrete

15). (i) If we select 100 persons out of 25,000 registered voters and question them about candidates and issues, the 100 persons are referred to as the population. (ii) The order that runners finish in a race would be an example of continuous data. (iii) Another name for inductive statistics is descriptive statistics. (Lind) A) (i), (ii) and (iii) are all correct statements. B) (i) and, (ii) are correct statements but not (iii). C) (i) and, (iii) are correct statements but not (ii). D) (ii) and, (iii) are correct statements but not (i). E) All statements are false.

E) All statements are false.

4) A researcher is gathering data from four geographical areas designated: South = 1; North = 2; East = 3; West = 4. The designated geographical regions represent a. qualitative data b. quantitative data c. label data d. either quantitative or qualitative data

a. qualitative data

5) A cumulative relative frequency distribution shows a. the proportion of data items with values less than or equal to the upper limit of each class b. the proportion of data items with values less than or equal to the lower limit of each class c. the percentage of data items with values less than or equal to the upper limit of each class d. the percentage of data items with values less than or equal to the lower limit of each class

a. the proportion of data items with values less than or equal to the upper limit of each class

3) The sum of frequencies for all classes will always equal a. 1 b. the number of elements in a data set c. the number of classes d. a value between 0 and 1

b. the number of elements in a data set

1) A frequency distribution is a. a tabular summary of a set of data showing the relative frequency b. a graphical form of representing data c. a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes d. a graphical device for presenting qualitative data

c. a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes

Exhibit 2-1 The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 - 9 20 10 - 19 80 20 - 29 200 30 - 39 100 7) Refer to Exhibit 2-1. The cumulative relative frequency for the class of 20 - 29 a. is 300 b. is 0.25 c. is 0.75 d. is 0.5

c. is 0.75