11.21 Consider the following pairs of measurements. D L11021 x y 54 5 4 33 3 -1 2 7 3 0 1 8 65 5 43 3 a. Construct a scatterplot of these data. b. What does the scatterplot suggest about the relation- ship between x and y? xx c. Given that SS = 43.4286, SSxy = 39.8571, y = 3.4286, and 3.7143, calculate the least squares estimates of Bo and B. 020; .918 d. Plot the least squares line on your scatterplot. Does the line appear to fit the data well? Explain. e. Interpret the y-intercept and slope of the least squares line. Over what range of x are these interpretations meaningful?

Consider the following data: Fit a line, y = x1 + x2t, to the data using the least squares approach.

12.21 In the study of Exercise 12.9, 25 observations were used to calculate the least squares estimates. The regression sum of squares and error sum of squares were found to be as follows: SSR 79.2 and SSE = 45.9 = a. Find and interpret the coefficient of determination. b. Find the adjusted coefficient of determination. c. Find and interpret the coefficient of multiple correlation.

The regional transit authority for a major metropolitan area wants to determine whetherthere is any relationship between the age of a bus and the annual maintenance cost. Asample of 10 buses resulted in the following data. Age of Bus (year) Maintenance Cost ($) 1 350 2 370 2 480 2 520 2 590 3 550 4 750 4 800 5 790 5 950 a. Develop the least squares estimated regression equation.b. Test to see whether the two variables are significantly related with α = .5.c. Did the least squares line provide a good fit to the observed data? Explain.d. Develop a 95% prediction interval for the maintenance cost for a specific bus thatis 4 years old.

The following table is an abbreviated life expectancy table for males.   current​ age, x 0 20 40 60 80 life​ expectancy, y 76.6 years 78.9 years 80.5 years 81.7 years 82.7 years   a. Find the straight line that provides the best​ least-squares fit for these data.

The following data represent the commute time (in minutes) x and a score on a well-being survey y. The equation of the least-squares regression line is y=-0.0468x + 68.9967 and the standard error of the estimate is 0.5157. Complete parts (a) through (e) below. X 5 T y 69.0 Lower Bound Upper Bound 15 25 35 50 72 105 68.2 67.4 67.1 66.8 66.5 63.6 (a) Predict the mean well-being index composite score of all individuals whose commute time is 20 minutes. y= (Round to two decimal places as needed.) (b) Construct a 90% confidence interval for the mean well-being index composite score of all individuals whose commute time is 20 minutes. = (Round to two decimal places as needed.) = (Round to two decimal places as needed.) G (c) Predict the well-being index composite score of Jane, whose commute time is 20 minutes. y= (Round to two decimal places as needed.) (d) Construct a 90% prediction interval for the well-being index composite score of Jane, whose commute time is 20 minutes. Lower Bound…

A state's park system statistical report for the 2014/2015 fiscal year gave the accompanying data on x = amount of money collected in user fees (in thousands of dollars) and y = operating cost (in thousands of dollars) for nine state parks in a certain district. 17 74 363 811 3,618 380 1,363 M 33 239 427 752 500 1,054 734 760 4000 (a) Construct a scatterplot of these data. 3000 User Fees Operating Costs (thousands of dollars) (thousands of dollars) 2000 1000 USE SALT 200 Need Help? 400 Submit Answer 600 99 Describe any interesting features of the scatterplot. There is a positive Read It 2,227 1,636 800 Watch It y 4000 3000 LILL 2000 1000 0 200 400 y 4000 3000 2000 1000 0 0 (b) Find the equation of the least squares line. (Round your answers to four decimal places.) ŷ = X + |× )x 200 400 linear relationship between user fees collected and operating costs. (c) Is the slope of the least squares line positive or negative? Is this consistent with your description of the scatterplot in part…

Please answer 4.13

Consider the following data. Do heavier cars really use more gasoline? Suppose a car is chosen at random. Let x be the weight of the car (in hundreds of pounds), and let y be the miles per gallon (mpg). The following information is based on data taken from Consumer Reports (Vol. 62, No. 4). x 27 47 32 47 23 40 34 52 y 30 22 23 13 29 17 21 14 Given the least squares line  = 40.9941 − 0.5263x: (a) Make a residual plot for the least-squares model. Be sure to plot the horizontal line at y = 0.         (b) Use the residual plot to comment about the appropriateness of the least squares model for these data. The residuals do not seem to be scattered randomly around the horizontal line at 0. There do not appear to be any outliers.The residuals seem to be scattered randomly around the horizontal line at 0. There do not appear to be any outliers.    The residuals do not seem to be scattered randomly around the horizontal line at 0. There do appear to be outliers.The residuals…

Given are five observations for two variables, and y. The estimated regression equation for these data is = 75.74-2.92x. a. Compute SSE, SST, and SSR. Yi The least squares line provided an - Select your answer decimal). fit; 4 SSE (to 2 decimals) SST (to 2 decimals) SSR (to 2 decimals) b. Compute the coefficient of determination ². Comment on the goodness of fit. (to 3 decimals) 00 15 18 20 57 57 46 17 12 Check My Work (2 remaining) % of the variability in y has been explained by the estimated regression equation (to 1 c. Compute the sample correlation coefficient. Enter negative value as negative number. (to 3 decimals)