Concept explainers
Education Expenditure The following chart shows the percentage of the U.S. discretionary budget allocated to education from 2003 to 2009. (
Source: www.globalissues.org/Geopolitics/ArmsTrade/Spending.asp
a. If you want to model the percentage figures with a function of the form
b. Which of the following models best approximates the data given? (Try to answer this without actually computing values.)
A.
B.
C.
D.
c. What is the nearest year that would correspond to the vertex of the graph of the correct model from part (b)? What is the danger of extrapolating the data in either direction?
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Chapter 2 Solutions
Applied Calculus
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- High School Graduates The following table shows the number, in millions, graduating from high school in the United States in the given year. Year Number graduating in millions 1985 2.83 1987 2.65 1989 2.47 1991 2.29 a. By calculating difference, show that these data can be modeled using a linear function. b. What is the slope for the linear function modeling high school graduations? Explain in practical terms the meaning of the slope. c. Find a formula for a linear function that models these data. d. Express, using functional notation, the number graduating from high school in 1994, and then use your formula from part c to calculate that value.arrow_forwardDemand for Candy Bars In this problem you will determine a linear demand equation that describes the demand for candy bars in your class. Survey your classmates to determine what price they would be willing to pay for a candy bar. Your survey form might look like the sample to the left. a Make a table of the number of respondents who answered yes at each price level. b Make a scatter plot of your data. c Find and graph the regression line y=mp+b, which gives the number of respondents y who would buy a candy bar if the price were p cents. This is the demand equation. Why is the slope m negative? d What is the p-intercept of the demand equation? What does this intercept tell you about pricing candy bars? Would you buy a candy bar from the vending machine in the hallway if the price is as indicated. Price Yes or No 50 75 1.00 1.25 1.50 1.75 2.00arrow_forwardDemand for Soft Drinks A convenience stores manager notices that sales of soft drinks are higher on hotter days, so he assembles the data in the table. a Make a scatter plot of the data. b Find and graph a linear function that models the data. c Use the model to predict soft drink sales if the temperature is 95. High temperature Number of cans sold 55 340 58 335 64 410 68 460 70 450 75 610 80 735 84 780arrow_forward
- The accompanying data represent the yearly amount of solar power installed (in megawatts) in a particular area from 2000 through 2008. The trend forecasting equations below were found, where X is the number of years after 2000. Complete parts (a) through (d) below. = -10.711 +28.9000X₁ ₁ = 22.70 +0.259X; +3.5801X? Click the icon to view the data table. a. Compute the standard error of the estimate (Syx) for each model. Linear Quadratic Syx 22.431 8.032 (Round to three decimal places as needed.) b. Compute the MAD for each model. Linear Quadratic MAD 64.222 66.873 (Round to three decimal places as needed.) c. On the basis of (a) and (b) and the principle of parsimony, which forecasting model would you select? The model with the smallest values of Syx and MAD should be used, which is the quadratic model.arrow_forwardThe amount of time adults spend watching television is closely monitored by firms because this helps to determine advertising pricing for commercials. Complete parts (a) through (d). (a) Do you think the variable "weekly time spent watching television" would be normally distributed? If not, what shape would you expect the variable to have? A. The variable "weekly time spent watching television" is likely normally distributed. B. The variable "weekly time spent watching television" is likely skewed right, not normally distributed. C. The variable "weekly time spent watching television" is likely symmetric, but not normally distributed. D. The variable "weekly time spent watching television" is likely skewed left, not normally distributed. E. The variable "weekly time spent watching television" is likely uniform, not normally distributed. (b) According to a certain survey, adults spend 2.35 hours per day watching television on a weekday. Assume that the standard deviation for "time spent…arrow_forward22. Clothing Men's shoe sizes are a linear function of foot length. a. Write an equation for a man's shoe size as a function of foot length. What men's size shoe is needed for a foot that measures 9.5 in.? Men's Shoe Sizes Foot Shoe Length (in.) Size 10 11 2INarrow_forward
- I need help solvingarrow_forward3. While shopping for a new car, Ms. McDonald collects data on age (in years) and price (in 1,000's of dollars) for used Honda Civics. First, Ms. McDonald ran a regression analysis on the data of Price versus Age. All logarithms are base 10. I. I. Price versus Age: (Computer output, scatterplot, residual plot) Predictor Constant Age Coef SE Coef 17.870 0.000 0.000 1.030 17.35 -1.4300 0.1276 -11.21 S 1.68336 R-Sq 89.34 R-Sq (adj) - 88.6%arrow_forward
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