Linear Equations

57.For each of the following situations, state the independent variable and the dependent variable.

a. A study is done to determine if elderly drivers are involved in more motor vehicle fatalities than other drivers.

The number of fatalities per 100,000 drivers is compared to the age of drivers.

b. A study is done to determine if the weekly grocery bill changes based on the number of family members.

c. Insurance companies base life insurance premiums partially on the age of the applicant.

d. Utility bills vary according to power consumption.

e. A study is done to determine if a higher education reduces the crime rate in a population.

Scatter Plots

59.The Gross Domestic Product Purchasing Power Parity is an indication of a country's currency value compared to another country.Table 12.16shows the GDP PPP of Cuba as compared to US dollars. Construct a scatter plot of the data.

Year - Cuba's PPP - Year - Cuba's PPP

1999, 1,700, 2006, 4,000

2000, 1,700, 2007, 11,000

2002, 2,300, 2008, 9,500

2003, 2,900, 2009, 9,700

2004, 3,000, 2010, 9,900

2005, 3,500,

Table 12.16

The Regression Equation

65.Explain what it means when a correlation has anr2 of 0.72.

Prediction

67.Recently, the annual number of driver deaths per 100,000 for the selected age groups was as follows:

Age - Number of Driver Deaths per 100,000

16-19 38

20-24 36

25-34 24

35-54 20

55-74 18

75+ 28

Table 12.19

a. For each age group, pick the midpoint of the interval for thexvalue. (For the 75+ group, use 80.)

b. Using "ages" as the independent variable and "Number of driver deaths per 100,000" as the dependent variable,

make a scatter plot of the data.

c. Calculate the least squares (best-fit) line. Put the equation in the form of:=a+bx

d. Find the correlation coefficient. Is it significant?

e. Predict the number of deaths for ages 40 and 60.

f. Based on the given data, is there a linear relationship between age of a driver and driver fatality rate?

g. What is the slope of the least squares (best-fit) line? Interpret the slope.

71.

# letters in Year entered the Rank for entering the Area (square name Union Union miles) ___ Colorado 1876 __= State 50\"\"? 13 1788 32,008 Carolina Table 12.23