## 111 terms

### True

A marketing research agency was hired to test a new DVD player. Consumers rated it outstanding, very good, fair, or poor. The level of measurement for this experiment is ordinal

### False

The Union of Electrical Workers of America with 9,128 members polled 362 members about a new wage package that will be submitted to management. The population is the 362 members.

### True

Based on a sample of 3,000 people, the civilian unemployment rate in the United States was Based on a sample of 3,000 people, the civilian unemployment rate in the United States was 5.5%. 5.5% is referred to as a statistic.

### True

The principal difference between the interval and ratio scale is that the ratio scale has a meaningful zero point.

### Tons of concrete to complete a parking lot

What is an example of a continuous variable?

Tons of concrete to complete a parking garage

Number of students in a statistics class

Zip codes of shoppers

Rankings of baseball teams in a league

### Advertisement does not include the total number of dentists surveyed.

When TV advertisements report "2 out of 3 dentists surveyed indicated they would recommend Brand X toothpaste to their patients," an informed consumer may question the conclusion because the

Sample was only 5 dentists.

Sample of dentists is clearly explained.

Advertisement does not include the total number of dentists surveyed.

Conclusion is not illustrated with a graph.

### Ordinal

A bank asks customers to evaluate the drive-thru service as good, average, or poor. Which level of measurement is this classification?

### Nominal

If Gallup, Harris, and other pollsters asked people to indicate their political party affiliation as Democrat, Republican, or Independent, the data gathered would be an example of which scale of measurement?

### Nominal

The members of each basketball team wear numbers on their jerseys. What scale of measurement are these numbers considered?

### Continuous

What type of variable is the number of gallons of gasoline pumped by a filling station during a day?

### Ordinal

The final rankings of the top 20 NCAA college basketball teams are an example of which level of measurement?

### Color of ink in a pen

An example of a qualitative variable is

Number of children in a family

Weight of a person

Color of ink in a pen

Miles between oil changes

### Number of miles between New York City and Chicago

Which one of the following is NOT an example of discrete data?

Number of households watching the Home Shopping Network

Number of employees reporting in sick

Number of miles between New York City and Chicago

Number of members of the Denver Lions Club

### True

A frequency distribution groups data into classes showing the number of observations in each class.

### False

To summarize the gender of students attending a college, the number of classes in a frequency distribution depends on the number of students.

### True

In frequency distributions, classes are mutually exclusive if each individual, object, or measurement is included in only one category.

### True

A class interval, or class width, can be determined by subtracting the lower limit of a class from the lower limit of the next higher class.

### True

To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the sum of the class frequencies.

### False

To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the number of classes.

### True

A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values.

### Upper and lower class limits must be calculated.

When data is collected using a quantitative, ratio variable, what is true about a frequency distribution that summarizes the data?

Upper and lower class limits must be calculated.

A pie chart can be used to summarize the data.

Number of classes is equal to the number of variable's values.

The "5 to the k rule" can be applied.

### A pie chart can be used to summarize the data.

When data is collected using a qualitative, nominal variable, what is true about a frequency distribution that summarizes the data?

The upper and lower class limits must be calculated.

A pie chart can be used to summarize the data.

The number of classes is equal to the number of variable's values plus 2.

The "5 to the k rule" can be applied.

### The number of classes corresponds to the number of a variable's values.

When data is collected using a qualitative, nominal variable (in other words, male or female), what is true about a frequency distribution that summarizes the data?

The upper and lower class limits must be calculated.

Class midpoints can be computed.

The number of classes corresponds to the number of a variable's values.

The "2 to the k rule" can be applied.

### Observations with values of 200 are excluded from the class

When a class interval is expressed as 100 up to 200,

Observations with values of 100 are excluded from the class

Observations with values of 200 are included in the class

Observations with values of 200 are excluded from the class

The class interval is 99

### The class frequency divided by the total frequency.

For a relative frequency distribution, relative frequency is computed as

The class width divided by class interval

The class midpoint divided by the class frequency

The class frequency divided by the class interval

The class frequency divided by the total frequency.

### Percent of observations in the class

The relative frequency for a class represents the

Class width

Class midpoint

Class interval

Percent of observations in the class

### Use a pie chart

A group of 100 students were surveyed about their interest in a new Economics major. Interest was measured in terms of high, medium, or low. In the study, 30 students responded high interest, 50 students responded medium interest, and 20 students responded low interest. What is the best way to illustrate the relative frequency of student interest?

Use a cumulative frequency polygon

Use a box plot

Use a pie chart

Use a frequency table

### The categories are not exhaustive.

A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify themselves as a Democrat or a Republican. This question is flawed because:

Students generally don't know their political preferences.

The categories are generally mutually exclusive.

The categories are not exhaustive.

Political preference is a continuous variable.

### Bar chart

A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify their political preference, for example, Democrat, Republican, Libertarian, or another party. The best way to illustrate the frequencies for each political preference is a __________.

Bar chart

Box plot

Histogram

Frequency polygon

### Frequency

In a frequency distribution, the number of observations in a class is called the class ________.

Midpoint

Interval

Array

Frequency

### To avoid a large number of empty classes

Why are unequal class intervals sometimes used in a frequency distribution?

To avoid a large number of empty classes

For the sake of variety in presenting the data

To make the class frequencies smaller

To avoid the need for midpoints

### False

In a company, the standard deviation of the ages of female employees is 6 years and the standard deviation of the ages of male employees is 10 years. These statistics indicate that the dispersion of age is greater for females than for males.

### False

According to Chebyshev's Theorem, 75% of the observations lie within plus and minus 2.00 average mean deviations.

### Mean

The sum of the deviations of each data value from this measure of central location will always be zero.

Mode

Mean

Median

Standard deviation

### Mean and median

For any data set, which measures of central location have only one value?

Mode and median

Mode and mean

Mode and standard deviation

Mean and median

### Mode and median

Which measures of central location are not affected by extremely small or extremely large values?

Mean and median

Mean and mode

Mode and median

Standard deviation and mean

### Median

For a data set, half of the observations are always greater than the ____.

Median

Mode

Mean

Standard deviation

### $46.51

A stockbroker placed the following order for a customer:

• 50 shares of Kaiser Aluminum at $104 a share

• 100 shares of GTE at $25.25 a share

• 20 shares of Boston Edison at $9.125 a share

What is the weighted arithmetic mean price per share?

$25.25

$79.75

$103.50

$46.51

### 54.5

The times (in minutes) that 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?

54.5

141.0

97.25

109.0

### Bimodal

Sometimes, a data set has two values that have the highest and equal frequencies. In this case, the distribution of the data can best be described as __________.

Symmetric

Bimodal (having two modes)

Positively skewed

Negatively skewed

### It can be biased by one or two extremely small or large values

A disadvantage of using an arithmetic mean to summarize a set of data is that __________.

The arithmetic mean sometimes has two values

It can be used for interval and ratio data

It is always different from the median

It can be biased by one or two extremely small or large values

### The life of Supplier B's tire is more predictable than the life of Supplier A's tires.

A purchasing agent for a trucking company is shopping for replacement tires for their trucks from two suppliers. The suppliers' prices are the same. However, Supplier A's tires have an average life of 60,000 miles with a standard deviation of 10,000 miles. Supplier B's tires have an average life of 60,000 miles with a standard deviation of 2,000 miles.

Which of the following statements is true?

The two distributions of tire life are the same.

On average, Supplier A's tires have a longer life than Supplier B's tires.

The life of Supplier B's tire is more predictable than the life of Supplier A's tires.

The dispersion of Supplier A's tire life is less than the dispersion of Supplier B's tire life.

### Zero

The sum of the differences between sample observations and the sample mean is equal to _______.

Zero

The mean deviation

The range

The standard deviation

### It uses absolute values.

What is a unique characteristic of the mean deviation?

It is based on only two observations.

It is based on deviations from the mean.

It uses absolute values.

It is only applied to skewed distributions.

### 2.4 kg

The weights of a sample of crates ready for shipment to Moscow, Russia are (in kilograms): 103, 97, 101, 106, and 103. What is the mean deviation?

0 kg

6.9 kg

102.0 kg

2.4 kg

### 110 and 190

The monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical, normal distribution. The sample mean is $150 and the standard deviation is $20. Using the Empirical Rule, about 95% of the monthly food expenditures are between what two amounts?

$100 and $200

$85 and $105

$205 and $220

$110 and $190

### 13.9 and 14.1 inches

The distribution of a sample of the outside diameters of PVC pipes approximates a symmetrical, bell-shaped distribution. The arithmetic mean is 14.0 inches, and the standard deviation is 0.1 inches. About 68% of the outside diameters lie between what two amounts?

13.5 and 14.5 inches

13.0 and 15.0 inches

13.9 and 14.1 inches

13.8 and 14.2 inches

### False

A student scored in the 85th percentile on a standardized test. This means that the student scored lower than 85% of all students who took the test.

### True

If a distribution is negatively skewed, the distribution is not symmetrical and the long tail is to the left.

### Median

In a distribution, the second quartile corresponds with the __________.

Mean

Median

Mode

Variance

### Cumulative frequency distribution

If a student places in the 99th percentile on an exam, she performed better than 99% of all students who completed the exam. Her performance is similar to a statement based on a __________.

Frequency table

Cumulative frequency distribution

Histogram

Pie chart

### The minimum, maximum, median, first and third quartiles.

What statistics are needed to draw a box plot?

The minimum, maximum, median, first and third quartiles.

The median, mean, and standard deviation.

The median and interquartile range.

The mean and standard deviation.

### 50

Using the following statistics to describe a distribution of data, what is the interquartile range?

Minimum = 10

Q1 = 25

Median = 50

Q3 = 75

Maximum = 95

85

50

15

20

### Symmetric

If the coefficient of skewness is equal to zero, the shape of the distribution is __________.

Negatively skewed

Symmetric

Positively skewed

Unknown

### -0.75

A large oil company is studying the number of gallons of gasoline purchased per customer at self-service pumps. The mean number of gallons is 10.0, with a standard deviation of 3.0 gallons. The median is 10.75 gallons. What is Pearson's coefficient of skewness in this instance?

-1.00

-0.75

+0.75

+1.00

### Two variables measured at the interval or ratio level

In a scatter diagram, we describe the relationship between __________.

Two variables measured at the ordinal level

Two variables, one measured as an ordinal variable and the other as a ratio variable

Two variables measured at the interval or ratio level

A variable measure on the interval or ratio level and time

### Two variables measured at the ordinal or nominal level

In a contingency table, we describe the relationship between ________.

Two variables measured at the ordinal or nominal level

Two variables, one measured as an ordinal variable and the other as a ratio variable

Two variables measured at the interval or ratio level

A variable measure on the interval or ratio level and time

### Company employees by gender and organizational title

A contingency table would be used to summarize data such as ________.

Company employees by gender and organizational title

Company employees by gender and age

Company employees by compensation and age

Company employees by compensation and years with the company

### True

The probability of rolling a 3 or 2 on a single die is an example of mutually exclusive events.

### True

An individual can assign a subjective probability to an event based on the individual's knowledge about the event.

### True

The joint probability of two independent events, A and B, is computed as P(A and B) = P(A) P(B).

### True

The joint probability of two events, A and B, that are not independent is computed as P(A and B) = P(A) P(B|A).

### False

A coin is tossed four times. The joint probability that all four tosses will result in a head is ¼ or 0.25.

### True

If there are "m" ways of doing one thing, and "n" ways of doing another thing, the multiplication formula states that there are (m) × (n) ways of doing both.

### True

The complement rule states that the probability of an event not occurring is equal to one minus the probability of its occurrence.

### True

An illustration of an experiment is turning the ignition key of an automobile as it comes off the assembly line to determine whether or not the engine will start.

### True

An illustration of an experiment is turning the ignition key of an automobile as it comes off the assembly line to determine whether or not the engine will start.

### P(A or B) = P(A) + P(B)

If two events A and B are mutually exclusive, what does the special rule of addition state?

P(A or B) = P(A) + P(B)

P(A and B) = P(A) + P(B)

P(A and/or B) = P(A) + P(B)

P(A or B) = P(A) - P(B)

### P(A) = 1 - P(not A)

What does the complement rule state?

P(A) = P(A) - P(B)

P(A) = 1 - P(not A)

P(A) = P(A) × P(B)

P(A) = P(A)X + P(B)

### Outcome

The result of a particular experiment is called a(n) ___________.

Observation

Conditional probability

Event

Outcome

### Joint probability

The probability of two or more events occurring concurrently is called a(n) _________.

Conditional probability

Empirical probability

Joint probability

Tree diagram

### The special rule of multiplication

If two events are independent, then their joint probability is computed with _________.

The special rule of addition

The special rule of multiplication

The general rule of multiplication

The Bayes theorem

### True

A probability distribution is a mutually exclusive and collectively exhaustive listing of experimental outcomes that can occur by chance, and their corresponding probabilities.

### True

To construct a binomial distribution, it is necessary to know the total number of trials and the probability of success on each trial.

### 0.735

Judging from recent experience, 5% of the computer keyboards produced by an automatic, high-speed machine are defective. If six keyboards are randomly selected, what is the probability that none of the keyboards are defective?

0.001

0.167

0.735

0.500

### All apply.

Which of the following is correct about a probability distribution?

The sum of all possible outcomes must equal 1.0.

Outcomes must be mutually exclusive.

The probability of each outcome must be between 0.0 and 1.0 inclusive.

All apply.

### 0.590

Carlson Jewelers permits the return of their diamond wedding rings, provided the return occurs within two weeks of the purchase date. Their records reveal that 10% of the diamond wedding rings are returned. Five different customers buy a wedding ring. What is the probability that none of the customers return a ring?

0.250

0.073

0.590

0.500