Stats Exam 1

Arithmetic operations provide meaningful results for variables that (a) can be converted to categories (b) appear as non-numerical values (c) are quantitative (d) have non-negative values

are quantitative

The most common graphical presentation of quantitative data is a (a) histogram (b) bar chart (c) stem and leaf display (d) pie chart

histogram

A numerical value used as a summary measure for a sample, such as sample mean, is known as a (a) population parameter (b) sample parameter (c) sample statistic (d) population mean

sample statistic

A graphical method that can be used to show both the rank order and shape of a distribution of data simultaneously is a (a) pie chart (b) relative frequency distribution (c) dot plot (d) stem-and-leaf display

stem-and-leaf display

The sum of frequencies for all classes will always equal (a) 1 (b) the number of observations in a data set (c) between 0 & 1 (d) the number of classes.

the number of observations in a data set

The correlation coefficient ranges between (a) 0 and 1 (b) -1 and 1 (c)−∞ and ∞ (d) 1and 100

-1 and 1

The variance of a sample of 169 observations equals 576. The standard deviation of the sample equals (a) 13 (b) 24 (c) 576 (d) 28,561

24

The variance of the sample (a) can never be negative (b) can be negative (c) cannot be zero (d) cannot be less than one

can never be negative

A researcher is gathering data from four geographical areas designated: South = 1; North = 2; East = 3; West = 4. The designated geographical regions represent what type of data? (a) categorical (b) quantitative(c) crosstabular (d) categorical or quantitative

categorical

In a questionnaire, respondents are asked to mark their gender as male or female. Gender is a (a) ordinal variable (b) continuous numerical variable (c) categorical variable (d) discrete numerical variable

categorical variable

An insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance. How long a person has been a licensed driver is an example of a ________ numerical variable

continuos

For a population frame containing N = 1,007 individuals, what code number should you assign to the first person on the list in order to use a table of random numbers?

0001

A population frame for a survey contains a listing of 6,179 names. Using a table of random numbers, which of the following code numbers will appear on your list?

0694

Which of the following is not a recommended guideline for creating an effective graphical display? (a) Give the display a clear and concise title (b) Use three dimensions whenever possible, to give the display depth (c) If colors are used to distinguish categories, use a legend to define them (d) Label each axis and show the units of measure

Use three dimensions whenever possible, to give the display depth

SCENARIO 1-2 A Wall Street Journal poll asked 2,150 adults in the U.S. a series of questions to find out their view on the U.S. economy. Referring to Scenario 1-2, the population of interest is

all the adults living in the U.S. when the poll was taken

An unusually small or unusually large data value is called (a) correlation coefficient (b) a deviation (c) an outlier (d) a variable

an outlier

Categorical data (a) indicate either how much or how many (b) cannot be numeric (c) are labels used to identify attributes of elements (d) must be nonnumeric

are labels used to identify attributes of elements

Fifteen percent of the students in a school of Business Administration are majoring in Economics, 20% in Finance, 35% in Management, and 30% in Accounting. The graphical device(s) which can be used to present these data is (are) (a) a line chart (b) only a bar chart (c) only a pie chart (d) both a bar chart and a pie chart

both a bar chart and a pie chart

The relative frequency (or relative count) of a class is computed by (a) dividing the cumulative frequency of a class by n. (b) dividing n by the cumulative frequency of the class. (c) dividing the frequency of the class by n. (d) dividing the frequency of the class by the number of classes.

dividing the frequency of the class by n.

The proper way to construct a stem-and-leaf display for the data set {62, 67, 68, 73, 73, 79, 91, 94, 95, 97} is to (a) exclude a stem labeled '8'. (b) include a stem labeled '8' and enter no leaves on the stem. (c) include a stem labeled '(8)' and enter no leaves on the stem. (d) include a stem labeled '8' and enter one leaf value of '0' on the stem.

include a stem labeled '8' and enter no leaves on the stem.

To find out the potential impact of a new zoning law on a neighborhood, the legislators conduct a focus group interview by inviting the members of the housing owners association of that neighborhood. This is an example of a

judgement sample

Referring to Scenario 1-3, if a customer survey questionnaire is included in all the Blu-ray players made and sold by the company over the past 12 months, this method of collecting data will most like suffer from

nonresponse error

A summary table shows the (a) fraction of items in several classes. (b) percentage of items in several classes. (c) relative percentage of items in several classes. (d) number of items in several classes.

number of items in several classes.

Collections of data on an individual or an item are (a) elements (b) populations (c) samples (d) observations

observations

Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example of a (a) ordinal variable (b) continuous numerical variable (c) categorical variable (d) discrete numerical variable

ordinal variable

A characteristic of interest for the elements is called a (a) variable (b) population (c) sample (d) observation

variable

The can be interpreted as the number of standard deviations a data value is from the mean of all the data values. (a) skewness (b) coefficient of variation (c) z-score (d) correlation coefficient

z-score

Which of the following sets of four numbers has the smallest standard deviation? (a) 7, 8, 9, 10 (b) 5, 5, 5, 6 (c) 0, 0, 10, 10 (d) 0, 1, 2, 3

5, 5, 5, 6

Which of the following is not a measure of variability? (a) range (b) 50th percentile (c) standard deviation (d) interquartile range

50th percentile

SCENARIO 1-1 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a Blu-ray player made by the company over the past 12 months are satisfied with their products. Referring to Scenario 1-1, the possible responses to the question "Are you happy, indifferent, or unhappy with the performance per dollar spent on the Blu-ray player?" are values from a ?

categorical variable

Referring to Scenario 1-1, the possible responses to the question "How much time do you use the Blu-ray player every week on the average?" are values from a ?

continuous numerical variable

Temperature is an example of a (a) ordinal variable (b) continuous numerical variable (c) categorical variable (d) discrete numerical variable

continuous numerical variable

To obtain a sample of 10 books in the store, the manager walked to the first shelf next to the cash register to pick the first 10 books on that shelf. This is an example of a

convenience sample

Referring to Scenario 1-1, the possible responses to the question "What is your annual income rounded to the nearest thousands?" are values from a ?

discrete numerical variable

The sample size (a) can be larger than the population size. (b) is always smaller than the population size. (c) can be larger or smaller than the population size. (d) is always equal to the size of the population.

is always smaller than the population size

When n − 1 is used in the denominator to compute variance, the data set (a) is sample (b) is a population (c) could be either a sample or population (d) is from a census

is sample

The measure of location which is the most likely to be influenced by extreme values in the data set is the (a) range (b) median (c) mode (d) mean

mean

Which of the following provides a measure of central location for the data? (a) standard deviation (b) mean (c) variance (d) range

mean

Your friend took an introductory statistics class last year and learned all about density curves. He draws a smooth curve with a long left tail. For such a curve, which of the following is true for the mean and median? (a) mean = median (b) mean > median (c) mean < median (d) Not enough information.

mean < median

The value which has half of the observations above it and half the observations below it is called the (a) median (b) mode (c) mean (d) range

median

If two groups of numbers have the same mean, then (a) their standard deviations must also be equal. (b) their medians must also be equal. (c) their modes must also be equal. (d) other measures of location need not be the same.

other measures of location need not be the same.

The interquartile range is (a) the 50th percentile (b) another name for the variance (c) the difference between the largest and smallest values (d) the difference between the third and first quartiles

the difference between the third and first quartiles

The collection of all elements of interest in a particular study is (a) the population (b) the sample (c) statistical inference (d) descriptive statistics

the population

In a random sample of 200 items, 5 items were defective. An estimate of the percentage of defective items in the population is (a) 5% (b) 2.5% (c) 20% (d) 10%

2.5%

The hourly wages of a sample of 130 system analysts are given below. mean = 60 range = 20 mode = 73 variance = 324 median = 74 The coefficient of variation equals (a) 0.30% (b) 30% (c) 5.4% (d) 54%

30%

A researcher has collected the following sample data. The mean of the sample is 5. 2 5 12 3 2 What is the standard deviation?

4.062

A population frame for a survey contains a listing of 72,345 names. Using a table of random numbers, how many digits will the code numbers for each member of your population contain?

5

A researcher has collected the following sample data. The mean of the sample is 5. 2 5 12 3 2 What is the interquartile range?

6.5

Referring to Scenario 1-3, if there are 4 different brands of Blu-ray players made by the company, the best sampling strategy would be to use a

a stratified sample

An insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance. The number of tickets a person has received in the last 3 years is an example of a ________ numerical variable

discrete

Income is an example of a (a) categorical variable (b) either categorical or quantitative variable (c) ordinal variable (d) quantitative variable

quantitative variable

Referring to Scenario 1-2, the 2,150 adults make up

the sample

Which of the following sampling methods is a probability sample? A) Quota sample B) Stratified sample C) Judgment sample D) Convenience sample

Stratified sample

SCENARIO 1-3 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a Blu-ray player made by the company over the past 12 months are satisfied with their products. Referring to Scenario 1-3, the manager decides to ask a sample of customers, who have bought a Blu-ray player made by the company and filed a complaint over the past year, to fill in a survey about whether they are satisfied with the product. This method will most likely suffer from

coverage error

The 75th percentile is referred to as the (a) first quartile (b) second quartile (c) third quartile (d) fourth quartile

third quartile