Concept explainers
Slopes of Lines in the Coordinate Plane For Exercises
Slope =
Find the slope of the line through the points
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Functions and Change: A Modeling Approach to College Algebra (MindTap Course List)
- The point-slope form of the equation of the line with slope 3 passing through the point 1, 2 is _.arrow_forwardWhen Date Are Unevenly speed. If data are evenly spaced, we need only calculate differences to see whether the data are linear. But if data not evenly spaced, then we must calculate the average rate of change over each interval to see whether the data are linear. If the average rate of changes is constant, it is the slope of the linear function. This fact is used in Exercises 23 and 24. In the following table, show that the average rate of change is the same over each interval. This shows the data are linear, even though the differences in y are not constant. Then find a linear model for the data. x 1 2 5 6 y 7 10 19 22arrow_forwardWhen Date Are Unevenly speed. If data are evenly spaced, we need only calculate differences to see whether the data are linear. But if data are not evenly spaced, then we must calculate the average rate of change over each interval to see whether the data are linear. If the average rate of change is constant, it is the slope of the linear function. This fact is used in Exercises 23 and 24. In the following table, show that the average rate of change from 2 to 5 is not the same as the average rate of change from 5 to 6. This shows that the data are not linear, even though the differences in y are constant. x 1 2 5 6 y 3 6 9 12arrow_forward
- Employee Turnover The percentage of employees who cease their employment during a year is referred to as employee turnover, and it is a serious issue for businesses. The following table shows the cost, in millions of dollars, to Walmart for a given employee turnover percentage in a year.13 E = employee turnover 10 20 30 40 C = cost 250 400 550 700 a. Show that the data can be modeled by a linear function. b. Find the slope of the linear function. c. Find a linear model for the data. d. Use the result from part c to find the cost to Walmart if employee turnover is 33 in a year.arrow_forwardDoes the following table represent a linear function ? If so, find the linear equation that models the data.arrow_forwardSlopes of Lines in the Coordinate Plane For Exercises S-14 through S-25, use the fact that for points (a1,b1) and (a2,b2) in the coordinate plane, we can calculate the slope of the line through these points using Slope = yx=b2b1a2a1. Find the slope of the line through the points (3.6,2.5)and(2.4,1.6).arrow_forward
- Price of Amazons Kindle The following table shows the price of Amazons Kindle 2 e-book reader. It is adapted from data available on the web. Here time is measured in months since February 2009, when the Kindle was launched. Time Price 0 349 5 299 10 249 15 199 a. By calculating differences, show that these data can be modeled using a linear function. b. Find a linear formula that models these data. Be careful about the sign of the slope. c. What price does your formula from part b project for January 2012 35 months after the Kindle was launched? Note: The web data were the basis for speculation that some day the Kindle would be free.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_forwardSlope If a building is 100 feet tall and is viewed from a spot on the ground 70 feet away from the base of the building, what is the slope of a line from the spot on the ground to the top of the building?arrow_forward
- Market supply The following table shows the quantity S of wheat, in billions of bushels, that wheat supplies are willing to produce in a year and offer for sale at a price P, in dollars per bushel. S = quantity of wheat P = price 1.0 1.35 1.5 2.40 2.0 3.45 2.5 4.50 In economics, it is customary to plot S on the horizontal axis and P on the vertical axis, so we will think of S as a variable and of P as a function of S. a. Show that these data can be modeled by a linear function, and find its formula. b. Make a graph of the linear formula you found in part a. This is called the market supply curve. c. Explain why the market supply curve should be increasing. Hint: Think about what should happen when the price increases. d. How much wheat would suppliers be willing to produce in a year and offer for sale at a price of 3.90 per bushel?arrow_forwardSuppose that average annual income (in dollars) forthe years 1990 through 1999 is given by the linearfunction: I(x)=1,054x+23,286 , where x is thenumber of years after 1990. Which of the followinginterprets the slope in the context of the problem? a. As of 1990, average annual income was $23,286. b. In the ten-year period from 1990-1999, averageannual income increased by a total of $1,054. c. Each year in the decade of the 1990s, averageannual income increased by $1,054. d. Average annual income rose to a level of $23,286 bythe end of 1999.arrow_forwardLife Expectancy Versus Health Care Spending One article shows a relationship between per capita health care spending h, in thousands of U.S. dollars per person per year, and life expectancy E, in years. The following formula is adapted from that article: E=72.23+3.85h0.37h2 We should point out that this article includes no justification for the type of model used. a.Plot the graph E versus h. Include spending levels from 1000 to 9000 per person per year so a horizontal span of 1 to 9. b. According to this model, what health care expenditure corresponds to maximum longevity? Round your answer in thousands of dollars per person per year to two decimal places. c.What optimum life expectancy is given by this model? For comparison, in 2011, in the United States, per capita health care spending was 8745 and life expectancy was 78.7 years.arrow_forward
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