Concept explainers
Skills and Applications
Agriculture An agricultural scientist used four test plots to determine the relationship between wheat yield
Fertilizer,
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Yield,
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a) Find the least squares regression line
b) Use the linear model from part (a) to estimate the yield for a fertilizer application of
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Precalculus (MindTap Course List)
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- 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_forwardDemand A hardware retailer wants to know the demand for a rechargeable power drill as a function of price. The ordered pairs (25,82),(30,75),(35,67), and (40,55) represent the price x in dollars and the corresponding monthly sales y. Find the least squares regression line for the data. Estimate the demand when the price is 32.95.arrow_forwardTemperature In Exercises 29 and 30, the figure shows the boundary temperatures in degree Celsius of an insulted thin metal plate. The steady-state temperature at an interior junction is approximately equal to the mean of the temperatures at the four surrounding junctions. Use a system of linear equations to approximate the interior temperatures T1,T2,T3, and T4.arrow_forward
- Adjusted Gross Income An individuals adjusted gross income is the amount of income that is subject to federal income tax. The following table shows the total adjusted gross income AGI, in trillions of dollars, reported to the IRS in the given year. Year 2009 2010 2011 2012 AGI trillions 7.6 8.1 8.6 9.1 a. Show that the data are linear. b. Let t denote the time in years since 2009, and let A denote the total adjusted gross income. Find a linear model for A as a function of t. c. Identify the slope of the linear model you found in part b, and explain its meaning in practical terms.arrow_forwardLife Expectancy The average life expectancy in the United States has been rising steadily over the past few decades, as shown in the table. (a) Make a scatter plot of the data. (b) Find and graph the regression line. (c) Use the linear model you found in part (b) to predict the life expectancy in the year 2006. (d) Search the Internet or your campus library to find the actual 2006 average life expectancy. Compare to your answer in part (c).arrow_forwardMarket Demand This is a continuation of Exercise 13. The following table shows the quantity D of wheat, in billions of bushels, that wheat consumers are willing to purchase in a year at a prince P, in dollars per bushel. D = quantity of wheat P = price 1.0 2.05 1.5 1.75 2.0 1.45 2.5 1.15 In economics, it is customary to plot D on the horizontal axis and P on the vertical axis, so we will think of D as a variable and of P as a function of D. a. Show that these data can be modeled by a linear function, and find its formula. b. Add the graph of the linear formula you found in part a, which is called the market demand curve, to your graph of the market supply curve from Exercise 13. c. Explain why the market demand curve should be decreasing. d. The equilibrium price is the price determined by the intersection of the market demand curve and the market supply curve. Find the equilibrium price determined by your graph in part b. 13. 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_forward
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