Concept explainers
Consider fitting the multiple regression model
A matrix of
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Statistics for Business and Economics (13th Edition)
- Cellular Phone Subscribers The table shows the numbers of cellular phone subscribers y in millions in the United States from 2008 through 2013. Source: CTIA- The Wireless Association Year200820092010201120122013Number,y270286296316326336 (a) Find the least squares regression line for the data. Let x represent the year, with x=8 corresponding to 2008. (b) Use the linear regression capabilities of a graphing utility to find a linear model for the data. How does this model compare with the model obtained in part a? (c) Use the linear model to create a table of estimated values for y. Compare the estimated values with the actual data.arrow_forwardThe least-squares regression equation is y=620.6x+16,624 where y is the median income and x is the percentage of 25 years and older with at least a bachelor's degree in the region. The scatter diagram indicates a linear relation between the two variables with a correlation coefficient of 0.7004. Predict the median income of a region in which 30% of adults 25 years and older have at least a bachelor's degree.arrow_forwardThe accompanying data represent the weights of various domestic cars and their gas mileages in the city. The linear correlation coefficient between the weight of a car and its miles per gallon in the city is r= - 0.977. The least-squares regression line treating weight as the explanatory variable and miles per gallon as the response variable is -0.0061x +41.3297. Complete parts (a) and (b) below. V = Click the icon to view the data table. (a) What proportion of the variability in miles per gallon is explained by the relation between weight of the car and miles per gallon? The proportion of the variability in miles per gallon explained by the relation between weight of the car and miles per gallon is %. (Round to one decimal place as needed.) (b) Interpret the coefficient of determination. % of the variance in is by the linear model. (Round to one decimal place as needed.) Data Table Full data set Miles per Miles per Weight (pounds), x Weight (pounds), x Car Car Gallon, y Gallon, y 1…arrow_forward
- The least-squares regression equation is y = 650.9x + 16,443 where y is the median income and x is the percentage of 25 years and older with at least a bachelor's degree in the region. The scatter diagram 55000- indicates a linear relation between the two variables with a correlation coefficient of 0.7174. Complete parts (a) through (d). 25000- 15 20 25 30 35 40 45 50 55 60 Bachelor's % (c) Interpret the slope. Select the correct choice below and fill in the answer box to complete your choice. (Type an integer or decimal. Do not round.) A. For 0% of adults having a bachelor's degree, the median income is predicted to be $ B. For a median income of $0, the percent of adults with a bachelor's degree is %. O C. For every dollar increase in median income, the percent of adults having at least a bachelor's degree is %, on average. O D. For every percent increase in adults having at least a bachelor's degree, the median income increases by $ , on average. Median Income ofarrow_forwardThe least-squares regression equation is y=784.6x+12,431 where y is the median income and x is the percentage of 25 years and older with at least a bachelor's degree in the region. The scatter diagram indicates a linear relation between the two variables with a correlation coefficient of 0.7962. In a particular region, 26.5 percent of adults 25 years and older have at least a bachelor's degree. The median income in this region is $29,889. Is this income higher or lower than what you would expect? Why?arrow_forwardthe following regression table where the dependent variable is the demandfor massage services in one city in the United States. Specifically, the dependent variable is the number of customers per hour (Models 1 and 2) or per day (Models 3 and 4). a) Explain why the coefficient for Population/1,000 in Model 2 is very different from the one in Model 4?arrow_forward
- Researchers are trying to assess the effectiveness of a new blood pressure medication. Using their data, they calculate a simple linear regression model that predicts systolic blood pressure (SBP) in terms of BP Meds (where 0 means the new medication is given and 1 means a placebo is give). The results are shown in the last row of the middle 2 columns of the table below. The researchers believe that Age, Gender, and BMI might be confounders. They calculate simple linear models for each of these variables as shown in the table where SBP is the response variable in each model. Then they calculate a multiple regression model that predicts SBP in terms of all 4 variables. The results are given in the last 2 columns on the table. Based on these results, is the association between BP meds and SBP confounded by Age, Gender or BMI? Provide a brief (1-2 sentences) explanation. Simple Models Multiple Regression b p b p Age 1.03 <.0001 0.86…arrow_forwardThe least-squares regression equation is y = 618.4x+ 17,572 where y is the median income and x is the percentage of 25 years and older with at least a bachelor's degree in the region. The scatter diagram indicates a linear relation between the two variables with a correlation coefficient of 0.6761. Complete parts (a) through (d). 55000- 20000- 15 20 25 30 35 40 45 50 55 60 Bachelor's % ..... (a) Predict the median income of a region in which 25% of adults 25 years and older have at least a bachelor's degree. (Round to the nearest dollar as needed.) (b) In a particular region, 29.2 percent of adults 25 years and older, have at least a bachelor's degree. The median income in this region is $38,940. Is this income higher than what you would expect? Why? This is than expected because the expected income is $ (Round to the nearest dollar as needed.) (c) Interpret the slope. Select the correct choice below and fill in the answer box to complete your choice. (Type an integer or decimal. Do…arrow_forward#11arrow_forward
- A faculty from the Mathematics Department wants to determine whether students aptitude test scores predict their perfaormance in statistics course. He randomly selected 10 students and recorded their aptitude test scores and final grade. Performance (Grade) in Aptitude Test Scores Statistics 95 90 87 85 90 88 78 75 83 80 90 80 88 90 75 60 93 90 77 78 • What is the correlation value of the 2 variables: • What linear regression equation best predicts performance in statistics, based on aptitude test scores? (ke Y 2.98 + 0.24x)arrow_forwardThe least-squares regression equation is y=660.8x +15,627 where y is the median income and x is the percentage of 25 years and older with at least a bachelor's degree in the region. The scatter diagram indicates a linear relation between the two variables with a correlation coefficient of 0.7527. Complete parts (a) through (d). 55000 20000- 15 20 25 30 35 40 45 50 55 60 Bachelor's % 東 测 (a) Predict the median income of a region in which 25% of adults 25 years and older have at least a bachelor's degree. $(Round to the nearest dollar as needed.) Median Incomearrow_forwardThe least-squares regression equation is y = 602.1x + 17,023 where y is the median income and x is the percentage of 25 years and older with at least a bachelor's degree in the region. The scatter diagram indicates a linear relation between the two variables with a correlation coefficient of 0.6748. Complete parts (a) through (d). This is (Round higher CE lower Median Income 55000- 25000- 15 20 25 30 35 40 45 50 55 60 Bachelor's % (a) Predict the median income of a region in which 25% of adults 25 years and older have at least a bachelor's degree. $32076 (Round to the nearest dollar as needed.) (b) In a particular region, 29.1 percent of adults 25 years and older have at least a bachelor's degree. The median income in this region is $37,759. Is this income higher than what you would expect? Why? than expected because the expected income is lar as needed.) Q 0arrow_forward
- Elementary Linear Algebra (MindTap Course List)AlgebraISBN:9781305658004Author:Ron LarsonPublisher:Cengage Learning