STAT 1100 Chapter 1-3 review

Consider the following sample data: {4, 7, -2, 9, 3, -6, 11, 7, 3, 11} What is the frequency of 4? a) 1 b) 10% c) 0.1 d) 0.1% e) 10

1

Consider the following sample data: {3, -2, 1, 0, -5, 3, 2, 0} What is the relative frequency of 0? a) 12.5% b) 2 c) 0.25% d) 0.125 e) 0.25

0.25

Consider the following sample data: {3, 7, -2, 1, -7, 0, -5, 3, 2, 0, 7, 7} What is the frequency of 7? a) 0.33 b) 4 c) 3 d) 33.3% e) 25%

3

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? a) 68% b) 95% c) 75% d) 99.7% e) Cannot be determined.

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? a) 81.5% b) 68% c) 32% d) 75% e) 95%

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? a) 95% b) 13.5% c) 5% d) 68% e) 75%

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? a) Cannot be determined. b) 99.7% c) 95% d) 75% e) 88.89%

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? a) 97.5% b) 81.5% c) 68% d) 95% e) 99.7%

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? a) 97% b) 97.5% c) 97.35% d) 81.5% e) 95%

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? a) 99.85% b) 2.5% c) 0.3% d) 99.7% e) 0.15%

99.85%

What is a population? a) Any specific collection of objects of interest. b) A group of people which can be either large or small. c) The United States of America. d) A large group of people. e) A large group of things, but it does not have to be people.

Any specific collection of objects of interest

What is a sample? a) A small group of people. b) All of these answer choices are correct. c) A small piece of something d) Any subset of the population. e) Any specific collection of objects of interest.

Any subset of the population.

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? a) 95% b) 2.5% c) 12.5% d) Cannot be determined. e) 75%

Cannot be determined.

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. a) None b) II only c) III only d) I, II and III e) I only

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 a) I and V only b) IV only c) II only d) III only e) III and IV only

III and IV only

The standard deviation of a numerical data set measures the ________ of the data. a) average b) variability c) range d) size e) most frequent value

variability

A random sample was taken of 3600 adults who were either employed or actively looking for employment. People were classified according to education and employment status. Under level of education "degree" means college or professional degree or higher. unemployed employed total no diploma 46 494 540 high school diploma 105 1947 2052 degree 29 979 1008 total 180 3420 3600 Suppose a person is selected at random. The probability that he is unemployed is about: a) .46 b) .35 c) .05 d) .95 e) .18

.05

A random sample was taken of 3600 adults who were either employed or actively looking for employment. People were classified according to education and employment status. Under level of education "degree" means college or professional degree or higher. unemployed employed total no diploma 46 494 540 high school diploma 105 1947 2052 degree 29 979 1008 total 180 3420 3600 Suppose a person is selected at random. The probability that he is unemployed, given that he has no high school diploma is about: a) .01 b) .34 c) .32 d) .09 e) .26

.09

The table below shows the results of a study on 175 people in which researchers examined the relationship between the presence of a certain mutated gene and colon cancer. Gene present Gene absent Total Patient has cancer 70 20 90 does not have cancer 25 60 85 Total 95 80 175 The probability that a randomly selected person is cancer free but has the mutated gene is closest to: a) .49 b) .29 c) .50 d) .71 e) .14

.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: a) .32 b) .84 c) .50 d) .68 e) .16

.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: a) .05 b) .68 c) .025 d) .32 e) .16

.16

A random sample was taken of 3600 adults who were either employed or actively looking for employment. People were classified according to education and employment status. Under level of education "degree" means college or professional degree or higher. unemployed employed total no diploma 46 494 540 high school diploma 105 1947 2052 degree 29 979 1008 total 180 3420 3600 Suppose a person is selected at random. The probability that he is either unemployed or has no high school diploma is about: a) .19 b) .09 c) .26 d) .20 e) .01

.19

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 Total Males 100 900 1000 Females 500 1500 2000 Total 600 2400 3000 What is the probability that this student is a nursing major? a) .20 b) .67 c) .80 d) .33 e) .30

.20

The table below shows the results of a study on 102 women in which researchers examined the association between the occurrence of a mutation of the BRCA gene and breast cancer. gene present gene absent Total Has cancer 33 19 52 Does not have cancer 39 11 50 Total 72 30 102 The probability that a randomly selected woman has cancer and the mutated gene is present is closest to a) .46 b) .27 c) .32 d) .71 e) .49

.32

The table below shows the results of a study on 102 women in which researchers examined the association between the occurrence of a mutation of the BRCA gene and breast cancer. gene present gene absent Total Has cancer 33 19 52 Does not have cancer 39 11 50 Total 72 30 102 The probability that a randomly selected woman does no have a cancer is closest to a) .29 b) .67 c) .34 d) .71 e) .49

.49

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 Total Males 100 900 1000 Females 500 1500 2000 Total 600 2400 3000 What is the probability that this student is a nursing major or a is male? a) 0.33 b) None of the above c) 0.03 d) .50 e) .20

.50

The table below shows the results of a study on 175 people in which researchers examined the relationship between the presence of a certain mutated gene and colon cancer. Gene present Gene absent Total Patient has cancer 70 20 90 does not have cancer 25 60 85 Total 95 80 175 The probability that a randomly selected person either has the mutated gene or has cancer is closest to: a) .51 b) .32 c) 1.06 d) .54 e) .66

.66

An integer is randomly selected between 1 and 50, inclusively. Find the probability that the number is not divisible by 7. a) .14 b) .70 c) .30 d) .88 e) .86

.86

The table below shows the results of a study on 102 women in which researchers examined the association between the occurrence of a mutation of the BRCA gene and breast cancer. gene present gene absent Total Has cancer 33 19 52 Does not have cancer 39 11 50 Total 72 30 102 The probability that a randomly selected woman has cancer or has the mutated gene, is closest to a) .892 b) .27 c) 1.216 d) .36 e) .75

.892

Use the following sample data: 3, -2, 1, 0, -5, 3, 2, 0, -1 The median of this data set is about: a) 0 b) -2.5 c) 0.5 d) -1 e) 0.1

0

Use the following sample data: 3, -2, 1, 0, -5, 3, 2, 0, -1 The mean of this data set is about: a) 1.7 b) -1.5 c) 2 d) 0.1 e) 0.3

0.1

A blood bank catalogs the types of blood, including positive or negative Rh-factor, given by donors during the last five days. the number of donors who gave each blood type is listed below. Suppose a donor is selected at random from this group of 409 donors. Blood Type O A B AB Total Rh-Positive 156 139 37 12 344 Rh-Negative 28 25 8 4 65 Total 184 164 45 16 409 Give that the selected donor has negative Rh-factor, find the probability that the donor has type B blood. a) 0.1231 b) 0.2162 c) 0.1076 d) 0.8222 e )0.1778

0.1231

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 a) 0.22 b) 0.14 c) 0.2 d) 0.18 e) 0.072

0.14

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 Total Female 42 2 44 Male 40 16 56 Total 82 18 100 What is the probability that this guest is unsatisfied? a) 0.82 b) 0.16 c) 0.44 d) 0.18 e) 0.88

0.18

Consider the following sample data: {3, -2, 1, 0, 2, -5, 3, 2, 0, 5} What is the relative frequency of 2? a) 0.2 b) 2 c) 30% d) 10% e) 3

0.2

The following table gives a two-way classification on gender and salary of 1000 employees in a company. <$40,000> >$40,000 Total Male 200 400 600 Female 150 250 400 Total 350 650 1000 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? a) 0.20 b) 0.35 c) 0.75 d) 0.65 e) 0.60

0.20

Use the data in the following two-way classification table, summarizing a random sample of 1200 young adults who were questioned about their age and where they live. Age 18 19 20 21 22 With parents 41 65 86 113 156 Elsewhere 212 179 153 105 90 Assume the proportions hold for all young adults from 18 to 22 years of age. A young adult is selected at random. The probability that he lives with his parents given that he is still a teenager (18 or 19) is about a) 0.31 b) 0.23 c) 0.19 d) 0.21 e) 7%

0.21

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 Total Male 600 250 850 Female 800 350 1150 Total 1400 600 2000 What's the probability that this person earned a Master's degree? a) 0.70 b) 0.40 c) 0.175 d) 0.30 e) 0.125

0.30

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 Total Males 100 900 1000 Females 500 1500 2000 Total 600 2400 3000 What is the probability that this student is a non-nursing major and is a male student? a) .20 b) 0.30 c) .80 d) .70 e) 0.03

0.30

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 a) 0.15 b) 0.35 c) 0.30 d) 0.00 e) 0.25

0.30

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 a) 0.50 b) 0.33 c) 0.67 d) 0.06 e) .01

0.33

Use the data in the following two-way classification table, summarizing a random sample of 1200 young adults who were questioned about their age and where they live. Age 18 19 20 21 22 With parents 41 65 86 113 156 Elsewhere 212 179 153 105 90 Assume the proportions hold for all young adults from 18 to 22 years of age. A young adult is selected at random. The probability that he lives with his parents is about a) 0.27 b) 0.53 c) 0.16 d) 0.62 e) 0.38

0.38

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 Total Male 600 250 850 Female 800 350 1150 Total 1400 600 2000 What's the probability that this person earned a Bachelor's degree and is a female? a) 0.60 b) 0.35 c) 0.30 d) 0.40 e) 0.70

0.40

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 Total Female 42 2 44 Male 40 16 56 Total 82 18 100 What is the probability that this guest is a male and is also satisfied with the service? a) 0.82 b) 0.42 c) 0.56 d) 0.18 e) 0.40

0.40

Use the data in the following two-way classification table, summarizing a random sample of 1200 young adults who were questioned about their age and where they live. Age 18 19 20 21 22 With parents 41 65 86 113 156 Elsewhere 212 179 153 105 90 Assume the proportions hold for all young adults from 18 to 22 years of age. A young adult is selected at random. The probability that he is still a teenager (18 or 19) is about a) 0.48 b) 0.22 c) 0.55 d) 0.41 e) 0.37

0.41

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 a) 0.55 b) 0.56 c) 0.44 d) 0.95 e) 0.45

0.55

The following table gives a two-way classification on gender and salary of 1000 employees in a company. <$40,000> >$40,000 Total Male 200 400 600 Female 150 250 400 Total 350 650 1000 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? a) 0.55 b) 0.60 c) 0.60 d) 0.65 e) 0.40

0.65

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 Total Male 600 250 850 Female 800 350 1150 Total 1400 600 2000 What's the probability that this person earned a Master's degree or is a female? a) 0.575 b) 0.175 c) 0.30 d) 0.70 e) 0.75

0.70

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: a) 0.61 b) 8.00 c) 0.78 d) 6.89 e) 7.00

0.78

The following table gives a two-way classification on gender and salary of 1000 employees in a company. <$40,000> >$40,000 Total Male 200 400 600 Female 150 250 400 Total 350 650 1000 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? a) 0.25 b) 0.75 c) 0.40 d) 0.65 e) 0.80

0.80

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 Total Female 42 2 44 Male 40 16 56 Total 82 18 100 What is the probability that this guest is a female or is satisfied with the service? a) 0.84 b) 0.56 c) 0.44 d) 0.82 e) None of the above

0.84

A blood bank catalogs the types of blood, including positive or negative Rh-factor, given by donors during the last five days. the number of donors who gave each blood type is listed below. Suppose a donor is selected at random from this group of 409 donors. Blood Type O A B AB Total Rh-Positive 156 139 37 12 344 Rh-Negative 28 25 8 4 65 Total 184 164 45 16 409 Find the probability that the donor has blood type O or type A blood. a) 0.3124 b) 0.8509 c) 0.8411 d) 0.7213 e) 0.1269

0.8509

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 a) 1.00 b) 0.95 c) 0.56 d) 0.45 e) 0.55

0.95

Use the following sample data: 3, -2, 4, 3, 0, 1, -2, 2 The sample mean computed from this data set is about: a) 1.3 b) 1.7 c) 2.1 d) 1.1 e) 1.8

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: a) 1.5 b) 3.0 c) 2.0 d) 1.3 e) 2.6

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: a) 2.1 b) 2.3 c) 1.5 d) 3.2 e) 5.3

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? a) 2.5% b) 47.5% c) 97.5% d) 0.15% e) 2.35%

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 μ = 30 and \sigma σ = 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. a) 32% b) 5% c) 16% d) 97.5% e) 2.5%

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: a) 2.4 b) 6.6 c) 9.5 d) 3.2 e) 2.6

2.6

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 a) 2.75 b) 1.50 c) 2.00 d) 3.01 e) 1.65

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? a) 5 b) 3 c) 0.2% d) 20% e) 33%

20%

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? a) 49.85% b) 99.7% c) 95% d) 68% e) 47.5%

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: a) 250 b) 2,000 c) Impossible to tell (not enough information given) d) 500 e) 1,500

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: a) 6.89 b) 6.00 c) 8.00 d) 7.55 e) 7.00

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: a) 8.00 b) 7.00 c) 6.50 d) 7.50 e) 6.00

7.00

What is a statistic? a) A number that summarizes some aspect of the population. b) A number which summarizes something, and is usually found in a report. c) A number which summarizes an athelete's performance. d) Usually a percentage. e)A number computed from sample data.

A number computed from sample data.

What is a parameter? a) A number computed from a sample. b) A measurement. c) A small part of a meter. d) A number that summarizes some aspect of the population. e) Something used to evaluate an outcome of an experiment.

A number that summarizes some aspect of the population.

The score made by a particular student on a national standardized exam is the 65th percentile. This means that: a) About 65% of all scores on the exam were higher than his. b) About 65% of all scores on the exam were lower than his. c) He got about 65% of the answers correct. d) His score is 65% of the average score. e) His score is the 65th best on the exam.

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: a) The 451 students in the survey who had off-campus jobs. b) All college students. c) All 1600 students surveyed. d) All college students who have off-campus jobs. e) Students in the Department of Education.

All college students.

A mother is told that her 13 year old son's height is the 85th percentile. This implies that: a) Eighty-five percent of all 13 year old boys have the same height of her son. b) Her son's height is more than that of 85% of all 13 year old boys. c) Her son's height is less than that of 85% of all 13 year old boys. d) Her son's height is 85% of the average height of all 13 year old boys. e) Her son has attained 85% of his adult height.

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

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: a) All statistics students. b) All of this professor's Introduction to Statistics students. c) The 270 students the professor emailed. d) All Introduction to Statistics students. e) All of this professor's students.

The 270 students the professor emailed.

Which one of the following is an example of quantitative data? a) Your hometown. b) The average number of children in a household. c) The least common major at a university. d) The governor of North Carolina. e) The most common eye color in a group of people.

The average number of children in a household.

Which one of the following is an example of qualitative data? a) The fastest animal on earth. b) Peter Pan's age. c) The average grade on an exam. d) The number of points scored by the losing team. e) The number of calories in an Oreo.

The fastest animal on earth.

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 μ = 30 and σ = 5.5 minutes. Suppose the distribution of finish times is approximately bell-shaped and symmetric. Which one of the statements is correct? a) The proportion of runners finished in under 24.5 minutes is approximately 95%. b) The proportion of runners finished in under 24.5 minutes is approximately 68%. c) The proportion of runners finished in under 30 minutes is greater that the proportion of runners finished above 30 minutes. d) The proportion of runners finished in under 30 minutes is less than the proportion of runners finished above 30 minutes. e) The proportion of runners finished in under 30 minutes is approximately equal to the proportion of runners finished above 30 minutes.

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

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? a) 99.7% b) 75% c) 97.35% d) 88.89% e) Cannot be determined.

cannot be determined

A random sample was taken of 3600 adults who were either employed or actively looking for employment. People were classified according to education and employment status. Under level of education "degree" means college or professional degree or higher. unemployed employed total no diploma 46 494 540 high school diploma 105 1947 2052 degree 29 979 1008 total 180 3420 3600 Suppose a person is selected at random. The events "U: unemployed" and "N: has no diploma" are: a) dependent because P(U) + P(N) ≠ 1 b) dependent because P(U and N) ≠ P(U)P(N) c) independent because P(U and N) ≠ P(U)P(N) d) independent because education and employment status are unrelated e) independent because P(U) + P(N) ≠ 1

dependent because P(U and N) \ne P(U)P(N)

The standard deviation of a numerical data set measures the _________ of the data. a) variability b) most frequent value c) range d) average e) size

variability