stats

The following table shows the estimated number (in thousands) of earned degrees conferred in USA in the year 2001 by level and gender. A person who earned a degree in the year 2001 is randomly selected. Bachelor's || Master's Male 600 || 250 Female 800 || 350 What's the probability that this person earned a Master's degree?

.30

The following table shows the number of male and female students enrolled in nursing program at an university. A student is randomly selected from this group. Nursing majors || Non-Nursing majors Males 100 || 900 Females 500 || 1500 What is the probability that this student is a non-nursing major and is a male student?

.30

There are seven intersections with traffic signals between Tristan's and Isolde's homes. If x denotes the number of signals at which Tristan must stop because of a red light on a randomly selected trip to Isolde's place, the probability distribution of x is X 0 1 2 3 4 P(X) 0.15 0.05 0.10 0.40 Tristan never has to wait at more than four of the signals The missing entry in the table is

.30

12% of all drivers do not have a valid driving license, 6% of all drivers have no insurance, 4% have neither. The probability that a randomly selected driver fails to have insurance, given that he fails to have a valid license is about

.33

The following table shows the estimated number (in thousands) of earned degrees conferred in USA in the year 2001 by level and gender. A person who earned a degree in the year 2001 is randomly selected. Bachelor's || Master's Male 600 || 250 Female 800 || 350 What's the probability that this person earned a Bachelor's degree and is a female?

.40

To determine whether its service is satisfactory to its customers, a hotel surveyed 100 guests and the result is summarized in the table below. A guest is randomly selected from these 100 people. Satisfied Unsatisfied Female 42 2 Male 40 16 What is the probability that this guest is a male and is also satisfied with the service?

.40

The following table shows the number of male and female students enrolled in nursing program at an university. A student is randomly selected from this group. Nursing majors || Non-Nursing majors Males 100 || 900 Females 500 || 1500 What is the probability that this student is a nursing major or a is male?

.50

Use the following sample data: 3, -2, 4, 3, 0, 1, -2, 2 The sample mean computed from this data set is about:

1.1

Use the following sample data: 3, -2, 4, 3, 0, 1, -2, 2 The sample median computed from this data set is about:

1.5

Use the following sample data: 3, -2, 4, 3, 0, 1, -2, 2 The sample standard deviation from this data set is about:

2.3

Consider a bell-shaped symmetric distribution with mean of 68 and standard deviation of 12. Approximately what percentage of data lie above 92?

2.5%

The annual 2-mile fun-run is a traditional fund-raising event to support local arts and sciences activities. It is known that the mean and the standard deviation of finish times for this event are respectively \mu = 30 and \sigma = 5.5 minutes. Suppose the distribution of finish times is approximately bell-shaped and symmetric. Find the approximate proportion of runners who finish in under 19 minutes.

2.5%

Use the following sample data: 3, -2, 1, 0, -5, 3, 2, 0, -1 The sample standard deviation of this data set is about:

2.6

The standard deviation of a numerical data set measures the ________ of the data.

variability

The standard deviation of a numerical data set measures the _________ of the data.

variability

There are seven intersections with traffic signals between Tristan's and Isolde's homes. If x denotes the number of signals at which Tristan must stop because of a red light on a randomly selected trip to Isolde's place, the probability distribution of x is X 0 1 2 3 4 P(X) 0.15 0.05 0.10 0.40 Tristan never has to wait at more than four of the signals The average number of intersections at which Tristan must stop because of a red light on trips to Isolde's place is

2.75

Consider the following sample data: {3, -5, 6, 5, 0, 7, -1, 5, -6, -5, 4, 1, 2, 5, 0} What is the relative frequency of 5?

20%

Consider the following sample data: {3, 7, -2, 1, -7, 0, -5, 3, 2, 0, 7, 7} What is the frequency of 7?

3

Consider a bell-shaped symmetric distribution with mean of 128 and standard deviation of 3. Approximately what percentage of data lie between 119 and 128?

49.85%

A charitable organization sends out 25,000 solicitations each month. The probability that a randomly selected solicitation will yield a contribution is .02 or 2%. The average number of contributions that result from each month is about:

500

5-lb bags of fresh peaches are sold at a farmers market. Nine such bags are randomly sampled and the number of peaches in each bag is noted as follows: 6, 7, 7, 7, 6, 8, 6, 7, 8 The mean of this data set is about:

6.89

5-lb bags of fresh peaches are sold at a farmers market. Nine such bags are randomly sampled and the number of peaches in each bag is noted as follows: 6, 7, 7, 7, 6, 8, 6, 7, 8 The median of this data set is about:

7

Consider a positively-skewed distribution with mean of 18 and standard deviation of 2.5. Approximately what percentage of data lie between 13 and 23?

75%

Consider a symmetric distribution which has no mode, a mean of 23 and standard deviation of 7. Approximately what percentage of data lie between 9 and 37?

75%

Consider a symmetric distribution which has two modes, a mean of 68 and standard deviation of 6. Approximately what percentage of data lie between 56 and 80?

75%

Consider a left-skewed distribution with mean of 68 and standard deviation of 12. Approximately what percentage of data lie between 32 and 104?

88.89%

Consider a bell-shaped symmetric distribution with mean of 16 and standard deviation of 1.5. Approximately what percentage of data lie between 13 and 19?

95%

Consider a bell-shaped symmetric distribution with mean of 68 and standard deviation of 6. Approximately what percentage of data lie between 50 and 80?

97.35%

Consider a bell-shaped symmetric distribution with mean of 24 and standard deviation of 6. Approximately what percentage of data lie above 6?

99.85%

A statistics professor wishes to estimate how much time Introduction to Statistics students spend studying for an exam. She emailed 270 randomly selected Introduction to Statistics students, and the average time spent by these students to study for an exam was 12 hours. The sample selected by this statistics professor is:

The 270 students the professor emailed

Which one of the following is an example of quantitative data?

The average number of children in a household

Which one of the following is an example of qualitative data?

The fastest animal on earth

The score made by a particular student on a national standardized exam is the 65th percentile. This means that:

About 65% of all scores on the exam were lower than his.

The Department of Education wishes to estimate the proportion of all college students who have a job off-campus. It surveyed 1600 randomly selected students; 451 had such jobs. The population of interest to the Department of Education is:

All college students

What is a population?

Any specific collection of objects of interest

What is a sample?

Any subset of the population

Use the following sample data: 3, -2, 1, 0, -5, 3, 2, 0, -1 The mean of this data set is about:

.1

12% of all drivers do not have a valid driving license, 6% of all drivers have no insurance, 4% have neither. The probability that a randomly selected driver either fails to have a valid license or fails to have insurance is about

.14

Heights in inches of 13 year old boys have a bell-shaped distribution with mean 61.5 and standard deviation 1.5. The proportion of all 13 year old boys who are at least 63 inches tall is about:

.16

The distribution of the lengths of a commercially caught fish in bell-shaped with a mean 26.8 cm and standard deviation 4.8 cm. Any fish measuring less than 22.0 cm must be released. The proportion of fish that must be released is about:

.16

To determine whether its service is satisfactory to its customers, a hotel surveyed 100 guests and the result is summarized in the table below. A guest is randomly selected from these 100 people. Satisfied Unsatisfied Female 42 2 Male 40 16 What is the probability that this guest is unsatisfied?

.18

Consider the following sample data: {3, -2, 1, 0, 2, -5, 3, 2, 0, 5} What is the relative frequency of 2?

.2

The following table gives a two-way classification on gender and salary of 1000 employees in a company. <$40,000> ||>$40,000 Male 200 || 400 Female 150 || 250 If one employee of this company is randomly selected, what's the probability that the person is male and the salary of this person is less than $40,000?

.20

The following table shows the number of male and female students enrolled in nursing program at an university. A student is randomly selected from this group. Nursing majors || Non-Nursing majors Males 100 || 900 Females 500 || 1500 What is the probability that this student is a nursing major?

.20

Professor Jackson is in charge of a program to prepare students for a high school equivalency exam. Records show that, in the program, 80% of the students need work in mathematics, 70% need work in English, and 55% need work in both areas. One person is to be randomly selected from this population of all students in the program. Let M = the selected person needs help in Mathematics E = the selected person needs help in English The probability that the selected person needs help in English and in Mathematics, i.e., P(E and M) is

.55

The following table gives a two-way classification on gender and salary of 1000 employees in a company. <$40,000> ||>$40,000 Male 200 || 400 Female 150 || 250 If one employee of this company is selected at random, what's the probability that the salary of the selected person is greater than $40,000?

.65

The following table shows the estimated number (in thousands) of earned degrees conferred in USA in the year 2001 by level and gender. A person who earned a degree in the year 2001 is randomly selected. Bachelor's || Master's Male 600 || 250 Female 800 || 350 What's the probability that this person earned a Master's degree or is a female?

.70

5-lb bags of fresh peaches are sold at a farmers market. Nine such bags are randomly sampled and the number of peaches in each bag is noted as follows: 6, 7, 7, 7, 6, 8, 6, 7, 8 The sample standard deviation of this data set is about:

.78

The following table gives a two-way classification on gender and salary of 1000 employees in a company. <$40,000> ||>$40,000 Male 200 || 400 Female 150 || 250 If one employee is randomly selected, what is the probability that the person is female or the salary of the person is greater than $40,000?

.80

To determine whether its service is satisfactory to its customers, a hotel surveyed 100 guests and the result is summarized in the table below. A guest is randomly selected from these 100 people. Satisfied Unsatisfied Female 42 2 Male 40 16 What is the probability that this guest is a female or is satisfied with the service?

.84

An integer is randomly selected between 1 and 50, inclusively. Find the probability that the number is not divisible by 7.

.86

Professor Jackson is in charge of a program to prepare students for a high school equivalency exam. Records show that, in the program, 80% of the students need work in mathematics, 70% need work in English, and 55% need work in both areas. One person is to be randomly selected from this population of all students in the program. Let M = the selected person needs help in Mathematics E = the selected person needs help in English The probability that the selected person needs help in English or in Mathematics, i.e., P(E or M) is

.95

Use the following sample data: 3, -2, 1, 0, -5, 3, 2, 0, -1 The median of this data set is about:

0

Consider the following sample data: {3, -2, 1, 0, -5, 3, 2, 0} What is the relative frequency of 0?

0.25

Consider the following sample data: {4, 7, -2, 9, 3, -6, 11, 7, 3, 11} What is the frequency of 4?

1

What is a statistic?

A number computed from sample data

What is a parameter?

A number that summarizes some aspect of the population

Consider a symmetric distribution which has no mode, a mean of 23 and standard deviation of 7. Approximately what percentage of data lie between 9 and 44?

Cannot be determined

Consider a symmetric distribution which has two mode, a mean of 47 and standard deviation of 7. Approximately what percentage of data lie above 61?

Cannot be determined

A mother is told that her 13 year old son's height is the 85th percentile. This implies that:

Her son's height is more than that of 85% of all 13 year old boys.

A sample data set contains n = 2 observations. Suppose one of the two observations is 1 and the sample standard deviation is s = 0. Identify the correct statement(s) among the following. I. Each of the two observations is 1. II. It is not possible to have a data set containing two observations and yet to have a variance equal to 0. III. The other observation must be -1.

I only

The variability of a sample data set is measured by which of the following statistics? I. most frequent value II. sample size III. range IV. standard deviation V. median

III an IV only

The annual 2-mile fun-run is a traditional fund-raising event to support local arts and sciences activities. It is known that the mean and the standard deviation of finish times for this event are respectively \mu = 30 and \sigma = 5.5 minutes. Suppose the distribution of finish times is approximately bell-shaped and symmetric. Which one of the statements is correct?

The proportion of runners finished in under 30 minutes is approximately equal to the proportion of runners finished above 30 minutes.