Use the following information to answer the next two exercises. A specialty cleaning company charges an equipment fee and an hourly labor fee. A linear equation that expresses the total amount of the fee the company charges for each session is y = 50 + 100x.

10. What are the independent and dependent variables?

11. What is the y-intercept and what is the slope? Interpret them using complete sentences.

Use the following information to answer the next two exercises. The price of a single issue of stock can fluctuate throughout the day. A linear equation that represents the price of stock for Shipment Express is y = 15 - 1.5x where x is the number of hours passed in an eight-hour day of trading.

15. What are the slope and y-intercept? Interpret their meaning.

Use the following information to answer the next five exercises. A random sample of ten professional athletes produced the following data where x is the number of endorsements the player has and y is the amount of money made (in millions of dollars).

x	y	x	y
0	2	5	12
3	8	4	9
2	7	3	9
1	3	0	3
5	13	4	10

25. What does an r value of zero mean?

Use the following information to answer the next two exercises. An electronics retailer used regression to find a simple model to predict sales growth in the first quarter of the new year (January through March). The model is good for 90 days, where x is the day. The model can be written as follows:

= 101.32 + 2.48x where is in thousands of dollars.

31. What would you predict the sales to be on day 60?

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

1. 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.
2. A study is done to determine if the weekly grocery bill changes based on the number of family members.
3. Insurance companies base life insurance premiums partially on the age of the applicant.
4. Utility bills vary according to power consumption.
5. A study is done to determine if a higher education reduces the crime rate in a population.

59. The Gross Domestic Product Purchasing Power Parity is an indication of a country's currency value compared to another country. The Table shows 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

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

1. For each age group, pick the midpoint of the interval for the x value. (For the 75+ group, use 80.)
2. 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.
3. Calculate the least squares (best-fit) line. Put the equation in the form of: = a + bx
4. Find the correlation coefficient. Is it significant?
5. Predict the number of deaths for ages 40 and 60.
6. Based on the given data, is there a linear relationship between age of a driver and driver fatality rate?
7. What is the slope of the least squares (best-fit) line? Interpret the slope.

69. The maximum discount value of the Entertainment card for the "Fine Dining" section, Edition ten, for various pages is given in the table.

Page number	Maximum value ($)
4	16
14	19
25	15
32	17
43	19
57	15
72	16
85	15
90	17

1. Decide which variable should be the independent variable and which should be the dependent variable.
2. Draw a scatter plot of the ordered pairs.
3. Calculate the least-squares line. Put the equation in the form of: = a + bx
4. Find the correlation coefficient. Is it significant?
5. Find the estimated maximum values for the restaurants on page ten and on page 70.

70. The Table gives the gold medal times for every other Summer Olympics for the women's 100-meter freestyle (swimming).

Year	Time (seconds)
1912	82.2
1924	72.4
1932	66.8
1952	66.8
1960	61.2
1968	60.0
1976	55.65
1984	55.92
1992	54.64
2000	53.8
2008	53.1

1. Decide which variable should be the independent variable and which should be the dependent variable.
2. Draw a scatter plot of the data.
3. Does it appear from inspection that there is a relationship between the variables? Why or why not?
4. Calculate the least squares line. Put the equation in the form of: = a + bx.
5. Find the correlation coefficient. Is the decrease in times significant?
6. Find the estimated gold medal time for 1932. Find the estimated time for 1984.
7. Why are the answers from part f different from the chart values?
8. Does it appear that a line is the best way to fit the data? Why or why not?
9. Use the least-squares line to estimate the gold medal time for the next Summer Olympics. Do you think that your answer is reasonable? Why or why not?