Concept explainers
Median Income The following table gives the median household income, meaning that half the households in the United States earned less than that amount and half the households earned more than that amount (see Chapter 10), for various years. (Data from: US. Census Bureau.)
Year | 2005 | 2010 | 2014 | 2015 |
Household Income | $46,326 | $49,276 | $53657 | $56,516 |
a. Use the data from the years 2005 and 2010 to find a linear model for these data, with a: = 5 corresponding to the year 2005.
b. Find the least-squares regression line for all these data.
c. Use the models in parts (a) and (b) to estimate the median household income for the year 2015 to the nearest dollar. Compare the estimates to the actual value for 2015.
d. Assuming the trend continues, use the model for part (b) to estimate the median household income for the year 2018 to the nearest dollar.
Want to see the full answer?
Check out a sample textbook solutionChapter 2 Solutions
MYMATHLAB ACCESS CODE - MATHEMATICS WIT
- Life Expectancy The following table shows the average life expectancy, in years, of a child born in the given year42 Life expectancy 2005 77.6 2007 78.1 2009 78.5 2011 78.7 2013 78.8 a. Find the equation of the regression line, and explain the meaning of its slope. b. Plot the data points and the regression line. c. Explain in practical terms the meaning of the slope of the regression line. d. Based on the trend of the regression line, what do you predict as the life expectancy of a child born in 2019? e. Based on the trend of the regression line, what do you predict as the life expectancy of a child born in 1580?2300arrow_forwardUsing your graphing calculator, make a scatter plot of the data from the table. Then graph your model from Question 2 along with the data. How well does your model fit the data? What could you do to try to improve your model?arrow_forwardSales Barnes & Noble had annual sales of $6.8 billion in 2013 and $6.1 billion in 2015. Use the Midpoint Formula to estimate the sales in 2014. Assume that the annual sales followed a linear pattern.arrow_forward
- Demand 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_forwardCell Phone Plans Gwendolyn is mulling over the three cell phone plans shown in the table. Gigabytes GB of data included Monthly Cost Each additional megabytes MB Plan A Plan B Plan C 1 1 1 25.00 40.00 60.00 2.00 1.50 1.00 From past experience, Gwendolyn knows that she will always use more than 1GB of cell phone data every month. aMake table of values that shows the cost of each plan for 1 GB to 4 GB, in 500 MB increments. bFind formulas that give Gwendolyns monthly cost for each plan, assuming that she uses x gigabytes of data per month where x1. cWhat is the charge from each plan when Gwendolyn uses 2.2 GB? 3.7 GB? 4.9 GB? d Use your formulas from part b to determine the number of gigabytes of data usage for which: (i) Plan A and Plan B give the same cost. (ii) Plan A and Plan C give the same cost. (iii) Plan B and Plan C give the same cost.arrow_forwardTEST YOUR UNDERSTANDING FOR EXAMPLE 3.6 The following table shows hypothetical enrollment E at a college t years after 2012. t = years since 2012 0 1 2 3 4 E = enrollment 8641 8975 9309 9643 9977 Show that the data are linear, and find a linear model for the data.arrow_forward
- 3.4 SKILL BUILDING EXERCISES Getting Regression Lines Only Find the equation of the regression line for the following data set. x 1 2 3 y 3 3 4arrow_forwardEmployee 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_forward
- Algebra and Trigonometry (MindTap Course List)AlgebraISBN:9781305071742Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage LearningFunctions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage LearningCollege AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage LearningGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill