## MATH 399N Week 1 MyStatLab Homework Solutions: Section 1.1, 1.2, 1.3, 2.2, 2.3, 2.4

##### MATH 399N Week 1 MyStatLab Homework Solutions (Version 1)

Section 1.1, 1.2, 1.3, 2.2, 2.3, 2.4

**1. Question: **Determine … the data set is a population or sample. Explain your reasoning.

The number of garages for each house on a street.

**2. Question: **Determine … the data set is a population or sample. Explain your reasoning.

The survey of 500 spectators from a stadium with 42000 spectators.

**3. Question: **Determine … the underlined value is a parameter or a statistic.

In a national survey of high school students (grades 9 to 12), __25%__ of respondents reported that someone had offered, sold, or given them an illegal drug on school property. Is the value a parameter or a statistic?

## STATUS

**4. Question: **Determine … the given value is a statistic or parameter.

In a study of all 2464 employees at a college, it is … that 45% own a television.

**5. Question: **Determine … the given value is a statistic or parameter.

In a study of all 2231 seniors at a college, it is … that 40% own a vehicle.

**6. Question: **Determine … the statement is true or false. If it is false, rewrite it as a true statement.

More types of calculators can … performed with data at the nominal level than with data at the interval level.

**7. Question: **Determine … the following statement is true or false, if it is false, rewrite it as a true statement.

Data at the ratio level cannot … put in order.

**8. Question: **The regions with the six highest volumes of sales for a corporation last year are shown below.

1. Eastern Southeast 3. Southwest 4. Southern

Determine … the data are qualitative or identify the data set’s level of measurement.

**9. Question: **Determine … the given description corresponds to an observational study or an experiment.

In a study of all 414 boys with a particular disease, the subjects drank herbal mixtures to determine if the mixtures have an effect on the disease.

**10. Question: 1.3.15 **A pharmaceutical company wants to test the effectiveness of a new allergy drug. The company identifies 250 females 30-35 years old who suffer from severe allergies. The subjects are randomly assigned into two groups. One group is given the new allergy drug and the other is given a placebo that looks exactly like the new allergy drug. After six months, the subjects’ symptoms are studied and … Answer parts (a) through (c) below.

**11. Question: **Identify the sampling techniques used, and discuss potential sources of bias (if any). Explain.

In 1965, researchers used random digit dialing to call 1100 people and ask what obstacles kept them from attending town hall meetings. What type of sampling was … ?

**12. Question: **Identify the sampling techniques used, and discuss potential sources of bias (if any). Explain. Assume the population of interest is the student body at a university.

Questioning students as they leave a university library, a researcher asks 371 students about their dating habits. What type of sampling was … ?

**13. Question: **Determine whether you would take a census or use a sampling to collect data for the study describe below.

The average height of the 45 employees of a company. Would you take a census or use a sampling?

**14. Question: **Match the plot with a possible description of the sample.

**15. Question: **Use a stem-and-leaf plot to display the data. The data represent the heights of eruptions by a geyser. What can you conclude about the data?

100 90 110

140 120 100

110 118 148

99 135 127

146 130 99

**16. Question: 2.3.11 **Determine whether the approximate shape of the distribution in the histogram is symmetric, uniform, skewed left, skewed right, or none of these.

**17. Question: 2.3.17 **The number of credits being taken by a sample of 13 full-time college students are listed below. Find the mean, median, and mode of the data, if possible. If any measure cannot be … or does not represent the center of the data.

4 4 7 7 4 5 3 3 3 3 3 3 6

**18. Question: 2.4.11 **The ages of 10 brides at their first marriage are given below. Complete parts (a) and (b) below.

25.6 37.2 34.7 26.4 43.6 29.4 23.7 30.6 32.3 29.9

(a) Find the range of the data set.

(b) Change 43.6 to 60.1 and find the range of the new data set

**19. Question: 2.4.15 **The ages (in years) of a random sample of shoppers at a gaming store are shown. Determine the range, mean, variance, and standard deviation of the sample data set.

12, 20, 23, 15, 15, 16, 20, 16, 14, 16

**20. Question: 2.4.31 **The mean value of land and buildings per acre from a sample of farms is $1600, with a standard deviation of $200. The data set has a bell-shaped distribution. Assume the number of farms in the sample is 80.

##### MATH 399N Week 1 MyStatLab Homework Solutions (Version 2)

Section 1.2, 1.3, 2.2, 2.3, 2.4

**1. Question**: **1.1.11 **Determine whether the data set is a population or a sample. Explain your reasoning.

The number of restaurants in each city in a state.

**2. Question: 1.1.15 **Determine whether the data set is a population or a sample. Explain your reasoning.

A survey of 500 spectators from a stadium with 42000 spectators

**3. Question: 1.1.35 **Determine whether the underlined value is a parameter or a static.

A study of 6076 adults in public rest rooms … that 23% did not wash their hands before exiting.

Is the value a parameter or a static?

**4. Question: 1.1.39 **Determine whether the given value is a statistic or a parameter.

In a study of all 2678 professors at a college, it is … that 25% own a television.

**5. Question: 1.1.41 **Determine whether the given value is a statistic or a parameter.

In a study of all 2846 professors at a college, it is … that 50% own a computer.

**6. Question: 1.2.5 **Determine whether the statement is true or false. If it is false, rewrite it as a true statement.

More types of calculations can … performed with data at the nominal level than with data at the interval level.

**7. Question: 1.2.6 **Determine whether the following statement is true or false. It is false, rewrite it as a true statement. Data at the ratio level cannot … put in order.

**8. Question: 1.2.27**

The region of a country with the highest level of food production for the past six years is shown below.

Southeast Northern Northwest Eastern Western

Determine whether the data are quantitative and identify the data sets level of measurement.

**9. Question: 1.3.13 **Determine whether the given description corresponds to an observational study or an experiment.

In a study of 372 girls with a particular disease, the subjects were given certain drugs to determine if the drugs have an effect on the disease.

Does the given description correspond to an observational study or an experiment?

**10. Question: 1.3.15 **A pharmaceutical company wants to test the effectiveness of a new allergy drug. The company identifies 250 females 30-35 years old who suffer from severe allergies. The subjects are randomly … into two groups. One group is given the new allergy drug and the other is given a placebo that looks exactly like the new allergy drug. After six months, the subjects’ symptoms are studied and compared. Answer parts (a) through (c) below.

**11. Question: 1.3.23 **Identify the sampling techniques used, and discuss potential sources of bias (if any). Explain.

In 1965, researchers used random digit dialing to call 900 people and ask what obstacles kept them from voting.

What type of sampling was … ?

**12. Question: 1.3.25 **Identify the sampling techniques used, and discuss potential sources of bias (if any). Explain. Assume the population of interest is the student body at a university.

Questioning students as they leave an academic building, a researcher asks 388 students about their dating habits.

**13. Question: 1.3.31 **Determine whether you would take a census or use a sampling to collect data for the study described below. The most popular grocery store among the 40000 employees of a company.

**14. Question: 2.2.5 **Match the plot with a possible description of the sample.

**15. Question: 2.2.17 **Use a stem-and-leaf plot to display the data. The data represent the heights of eruptions by a geyser. What can you conclude about the data?

105 90

140 120

110 114

99 138

143 130

**16. Question: 2.3.11 **Determine … the approximate shape of the distribution in the histogram is symmetric, uniform, skewed left, skewed right, or none of these.

**17. Question: 2.3.17 **The number of credits … taken by a sample of 13 full-time college students are … below. Find the mean, median, and mode of the data, if possible. If any measure cannot … or does not represent the center of the data.

5 5 8 8 5 6 4 4 4 4 4 4 7

**18. Question: 2.4.11 **The ages of 10 brides at their first marriage are … Complete parts (a) and (b) below.

28.6 24.1 33.4 24.9 45.7 24.7 26.9 30.1 26.8 29.5

**19. Question: 2.4.15 **The ages (in years) of a random sample of shoppers at a gaming store are … the range, mean, variance, and standard deviation of the sample data set.

12, 18, 23, 15, 16, 16, 20, 17, 13, 18

**20. Question: 2.4.29 **Heights of men on a baseball team have a bell-shaped distribution with a mean 0f 167 cm and a standard deviation of 5 cm. using the empirical rule, what is the approximate percentage of the men between the following values?

162 cm and 172 cm

157 cm and 177 cm

**21. Question: 2.4.31 **The mean value of land and buildings per acre from a sample of farms is $1700, with a standard deviation of $200. The data set has a bell-shaped distribution. Assume the number of farms in the sample is 77.