Construct a pie chart for these dat b. Construct a bar chart for these dat

Business February 2002 provide the data given in the following table. The numbers reported are in thousands of units—that is, 9,436 represents 9,436,000 vehicles sold in 1990. Year Type of Vehicle 1990 1995 1997 1998 1999 2000 2001 2002 Passenger Car 9,436 8,687 8,273 8,142 8,697 8,852 8,422 8,082 SUVLight Truck 4,733 6,517 7,226 7,821 8,717 8,965 9,050 9,036 a. Would pie charts be appropriate graphical summaries for displaying these data? Why or why not?

b. Construct a bar chart that would display the changes across the 12 years in the public’s

choice in vehicle. c. Do you observe a trend in the type of vehicles purchased? Do you feel this trend will continue if there was a substantial rise in gasoline prices? Med. 3.3 It has been reported that there has been a change in the type of practice physicians are selecting for their career. In particular, there is concern that there will be a shortage of family practice physicians in future years. The following table contains data on the total number of office- based physicians and the number of those physicians declaring themselves to be family practice physicians. The numbers in the table are given in thousands of physicians. Source: Statistical Abstract of the United States: 2003 Year 1980 1990 1995 1998 1999 2000 2001 Family Practice 47.8 57.6 59.9 64.6 66.2 67.5 70.0 Total Office-Based Physicians 271.3 359.9 427.3 468.8 473.2 490.4 514.0

a. Use a bar chart to display the increase in the number of family practice physicians

from 1990 to 2002.

b. Calculate the percent of office-based physicians who are family practice physicians and

then display this data in a bar chart. c. Is there a major difference in the trend displayed by the two bar charts? Env.

3.4 The regulations of the board of health in a particular state specify that the fluoride level

must not exceed 1.5 parts per million ppm. The 25 measurements given here represent the fluoride levels for a sample of 25 days. Although fluoride levels are measured more than once per day, these data represent the early morning readings for the 25 days sampled. .75 .86 .84 .85 .97 .94 .89 .84 .83 .89 .88 .78 .77 .76 .82 .72 .92 1.05 .94 .83 .81 .85 .97 .93 .79 a. Determine the range of the measurements. b. Dividing the range by 7, the number of subintervals selected, and rounding, we have a class interval width of .05. Using .705 as the lower limit of the first interval, construct a frequency histogram.

c. Compute relative frequencies for each class interval and construct a relative frequency

histogram. Note that the frequency and relative frequency histograms for these data have the same shape.

d. If one of these 25 days were selected at random, what would be the chance probability

that the fluoride reading would be greater than .90 ppm? Guess predict what propor- tion of days in the coming year will have a fluoride reading greater than .90 ppm. Gov. 3.5 The National Highway Traffic Safety Administration has studied the use of rear-seat auto- mobile lap and shoulder seat belts. The number of lives potentially saved with the use of lap and shoulder seat belts is shown for various percentages of use. Lives Saved Wearing Percentage of Use Lap Belt Only Lap and Shoulder Belt 100 529 678 80 423 543 60 318 407 40 212 271 20 106 136 10 85 108 Suggest several different ways to graph these data. Which one seems more appropriate and why? Soc. 3.6 As the mobility of the population in the United States has increased and with the increase in home-based employment, there is an inclination to assume that the personal income in the United States would become fairly uniform across the country. The following table provides the per capita personal income for each of the 50 states and the District of Columbia. Income thousands of dollars Number of States 22.0 –24.9 5 25.0 –27.9 13 28.0 –30.9 16 31.0 –33.9 9 34.0 –36.9 4 37.0 –39.9 2 40.0 – 42.9 2 Total 51 a. Construct a relative frequency histogram for the income data. b. Describe the shape of the histogram using the standard terminology of histograms.

c. Would you describe per capita income as being fairly homogenous across the

United States? Med. 3.7 The survival times in months for two treatments for patients with severe chronic left- ventricular heart failure are given in the following tables. Standard Therapy New Therapy 4 15 24 10

1 27

31 5 20 29 15 7 32 36 14 2 16 32 7 13 36 17 15 19 35 10 16 39 29 6 12 18 14 15

18 27

14 10 16 12 13 16 6 13 21 20 8 3 24 9 18 33 30 29 31 27

a. Construct separate relative frequency histograms for the survival times of both the

therapies.

b. Compare the two histograms. Does the new therapy appear to generate a longer

survival time? Explain your answer.