Exam 2: Organizing and Visualizing Variables

When constructing a frequency distribution, classes should be selected so that they are of equal width.

SCENARIO 2-13 Given below is the stem-and-leaf display representing the amount of detergent used in gallons (with leaves in 10ths of gallons) in a day by 25 drive-through car wash operations in Phoenix. 9\mid147 10\mid02238 11\mid135566777 12\mid223489 13\mid02 -Referring to Scenario 2-13, construct a percentage polygon for the detergent data if the corresponding frequency distribution uses "9.0 but less than 10.0" as the first class.

SCENARIO 2-5 The following are the duration in minutes of a sample of long-distance phone calls made within the continental United States reported by one long-distance carrier. Time(inMinutes) Relative Frequency 0 but less than 5 0.37 5 but less than 10 0.22 10 but less than 15 0.15 15 but less than 20 0.10 20 but less than 25 0.07 25 but less than 30 0.07 30 or more 0.02 -Referring to Scenario 2-5, if 1,000 calls were randomly sampled, how many calls lasted under 10 minutes?

SCENARIO 2-6 A sample of 200 students at a Big-Ten university was taken after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm.The following table contains the result. Did Well in Midterm Did Poorly in Midterm Studying for Exam 80 20 Went Bar Hopping 30 70 -Referring to Scenario 2-6, if the sample is a good representation of the population, we can expectpercent of those who spent the weekend studying to do poorly on the midterm.

In general, a frequency distribution should have at least 8 class groups but no more than 20.

SCENARIO 2-12 The table below contains the opinions of a sample of 200 people broken down by gender about the latest congressional plan to eliminate anti-trust exemptions for professional baseball. For Neutral Against Totals Female 38 54 12 104 Male 12 36 48 96 Totals 50 90 60 200 -Referring to Scenario 2-12, of the females in the sample, percent were against the plan.

Given below is the scatter plot of the number of employees and the total revenue ($millions) of 20 U.S.companies.Companies that have higher numbers of employees appear to also have higher total revenue.

SCENARIO 2-9 The frequency distribution below represents the rents of 250 randomly selected federally subsidized apartments in a small town. Rentin \ Frequency 1,100 but less than 1,200 113 1,200 but less than 1,300 85 1,300 but less than 1,400 32 1,400 but less than 1,500 16 1,500 but less than 1,600 4 -Referring to Scenario 2-9, percent of the apartments rented for $1,400 or more.

Apple Computer, Inc.collected information on the age of their customers.Suppose the youngest customer was 12 and the oldest was 72.To study the distribution of the age among its customers, it can use a percentage polygon.

SCENARIO 2-14 The table below contains the number of people who own a portable Blu-ray player in a sample of 600 broken down by gender. Own a Portable Blu-ray player Male Female Yes 96 40 No 224 240 -Referring to Scenario 2-14, construct a table of row percentages.

SCENARIO 2-12 The table below contains the opinions of a sample of 200 people broken down by gender about the latest congressional plan to eliminate anti-trust exemptions for professional baseball. For Neutral Against Totals Female 38 54 12 104 Male 12 36 48 96 Totals 50 90 60 200 -Referring to Scenario 2-12, if the sample is a good representation of the population, we can expect percent of the males in the population will be against the plan.

Given below is the scatter plot of the market value (thousands$) and profit (thousands$) of 50 U.S.companies.There appears to be a negative relationship between market value and profit.

SCENARIO 2-13 Given below is the stem-and-leaf display representing the amount of detergent used in gallons (with leaves in 10ths of gallons) in a day by 25 drive-through car wash operations in Phoenix. 9\mid147 10\mid02238 11\mid135566777 12\mid223489 13\mid02 -Referring to Scenario 2-13, construct a cumulative percentage polygon for the detergent data if the corresponding frequency distribution uses "9.0 but less than 10.0" as the first class.

SCENARIO 2-1 An insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance.A representative from a local insurance agency selected a random sample of insured drivers and recorded, X, the number of claims each made in the last 3 years, with the following results. X f 1 14 2 18 3 12 4 5 5 1 -Referring to Scenario 2-1, how many total claims are represented in the sample?

The Best Practices for Creating Visual Summaries recommend avoiding uncommon chart type such as doughnut, radar, cone and pyramid charts.

Determining the class boundaries of a frequency distribution is highly subjective.

SCENARIO 2-9 The frequency distribution below represents the rents of 250 randomly selected federally subsidized apartments in a small town. Rentin \ Frequency 1,100 but less than 1,200 113 1,200 but less than 1,300 85 1,300 but less than 1,400 32 1,400 but less than 1,500 16 1,500 but less than 1,600 4 -Referring to Scenario 2-9, the class midpoint of the second class is .

One of the advantages of a pie chart is that it clearly shows that the total of all the categories of the pie adds to 100%.

One of the developing countries is experiencing a baby boom, with the number of births rising for the fifth year in a row, according to a BBC News report.Which of the following is best for displaying this data?

SCENARIO 2-10 The relative frequency histogram below represents scores achieved by 200 job applicants on a personality profile. -Referring to the histogram from Scenario 2-10, percent of the applicants scored between20 and below 50.