Concept explainers
Regression and Predictions. Exercises 13-28 use the same data sets as Exercises 13-28 in Section 10-1. In each case, find the regression equation, letting the first variable be the predictor (x) variable. Find the indicated predicted value by following the prediction procedure summarized in Figure 10-5 on page 493.
27. Sports Using the diameter/circumference data, find the best predicted circumference of a marble with a diameter of 1.50 cm. How does the result compare to the actual circumference of 4.7 cm?
28. Sports Using the diameter/volume data from the preceding exercise, find the best predicted volume of a marble with a diameter of 1.50 cm. How does the result compare to the actual volume of 1.8 cm3?
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- Olympic Pole Vault The graph in Figure 7 indicates that in recent years the winning Olympic men’s pole vault height has fallen below the value predicted by the regression line in Example 2. This might have occurred because when the pole vault was a new event there was much room for improvement in vaulters’ performances, whereas now even the best training can produce only incremental advances. Let’s see whether concentrating on more recent results gives a better predictor of future records. (a) Use the data in Table 2 (page 176) to complete the table of winning pole vault heights shown in the margin. (Note that we are using x=0 to correspond to the year 1972, where this restricted data set begins.) (b) Find the regression line for the data in part ‚(a). (c) Plot the data and the regression line on the same axes. Does the regression line seem to provide a good model for the data? (d) What does the regression line predict as the winning pole vault height for the 2012 Olympics? Compare this predicted value to the actual 2012 winning height of 5.97 m, as described on page 177. Has this new regression line provided a better prediction than the line in Example 2?arrow_forwardRegression and Predictions. Exercises 13–28 use the same data sets as Exercises 13–28 in Section 10-1. In each case, find the regression equation, letting the first variable be the predictor (x) variable. Find the indicated predicted value by following the prediction procedure summarized in Figure 10-5 on page 493. Crickets and Temperature Find the best predicted temperature at a time when a cricket chirps 3000 times in 1 minute. What is wrong with this predicted temperature?arrow_forwardRegression and Predictions. Exercises 13–28 use the same data sets as Exercises 13–28 in Section 10-1. In each case, find the regression equation, letting the first variable be the predictor (x) variable. Find the indicated predicted value by following the prediction procedure summarized in Figure 10-5 on page 493. Oscars Using the listed actress/actor ages, find the best predicted age of the Best Actor given that the age of the Best Actress is 54 years. Is the result reasonably close to the Best Actor’s (Eddie Redmayne) actual age of 33 years, which happened in 2015, when the Best Actress was Julianne Moore, who was 54 years of age?arrow_forward
- Section 10.2 Question #12 Find the regression equation, letting the diameter be the predictor (x) variable. Find the best predicted circumference of a marblewith a diameter of 1.2 cm. How does the result compare to the actual circumference of 3.8 cm? Use a significance level of 0.05. Baseball Basketball Golf Soccer Tennis Ping-Pong Volleyball Diameter 7.5 24.3 4.2 21.7 6.9 4.1 20.7 Circumference 23.6 76.3 13.2 68.2 21.7 12.9 65.0 View the critical values of the Pearson correlation coefficient r. Critical values of the pearson correlation coefficient r n α=0.05 α=0.01 NOTE: To test H0: ρ=0 against H1: ρ≠0, reject H0 if the absolute value of r is greater than the critical value in the table. 4 0.950 0.990 5 0.878 0.959 6 0.811 0.917 7 0.754 0.875 8 0.707 0.834 9 0.666 0.798 10 0.632 0.765 11 0.602 0.735 12 0.576…arrow_forwardRegression and Predictions. Exercises 13–28 use the same data sets as Exercises 13–28 in Section 10-1. In each case, find the regression equation, letting the first variable be the predictor (x) variable. Find the indicated predicted value by following the prediction procedure summarized in Figure 10-5 on page 493. Old Faithful Using the listed duration and interval after times, find the best predicted “interval after” time for an eruption with a duration of 253 seconds. How does it compare to an actual eruption with a duration of 253 seconds and an interval after time of 83 minutes?arrow_forwardSection 10.2 Question #8 Find the regression equation, letting the first variable be the predictor (x) variable. Using the listed lemon/crash data, where lemon imports are in metric tons and the fatality rates are per 100,000 people, find the best predicted crash fatality rate for a year in which there are 450metric tons of lemon imports. Is the prediction worthwhile? Lemon Imports 226 270 364 488 525 Crash Fatality Rate 16.1 15.9 15.6 15.5 15.1 Find the equation of the regression line. y= ___________+( ____________)x (Round the y-intercept to three decimal places as needed. Round the slope to four decimal places as needed.) The best predicted crash fatality rate for a year in which there are 450 metric tons of lemon imports is _________ fatalities per 100,000 population. (Round to one decimal place as needed.)arrow_forward
- Chapter 9, Section 1, Exercise 006 Computer output for fitting a simple linear model is given below. State the value of the sample slope for this model and give the null and alternative hypotheses for testing if the slope in the population is different from zero. Identify the p-value and use it (and a 5% significance level) to make a clear conclusion about the effectiveness of the model.The regression equation is Y=81.0-0.0155X. Predictor Coef SE Coef T P Constant 80.96 11.62 6.97 0.000 X -0.01546 0.01288 -1.20 0.245arrow_forwardThe regression model Yi=−303.8+1.5949X1i−0.0699X2i predicts standby hours based on total staff present, X1i, and remote hours, X2i, for week i. The data from which the model was constructed are provided. b. If appropriate, perform the Durbin-Watson test, using α=0.05. Determine the Durbin-Watson statistic.arrow_forwarda. find the equation of the regression line? b. the best-predicted crash fatality rate for a year in which there are 500 metric tons of lemon imports is _?_ facilitates per 100,000 population,arrow_forward
- a)Find the equation of the least-squares regression line for the data. (Where x is the independent variable.) Round constants to the nearest hundredth. b)Use the equation from part (a) to determine, to the nearest centimeter, the projected wingspan of a pterosaur if its humerus is 53 centimeters.arrow_forwardDiscuss the reasons and situations in which researchers would want to use linear regression? How would a researcher know whether linear regression would be the appropriate statistical technique to use? What are some of the benefits of fitting the relationship between two variables to an equation for a straight line? Give an example of data that can be modeled by using linear regression.arrow_forwardThe data lists the average gestation period (in days) and longevity (in years) for a sample of animals, as reported in The World Almanac and Book of Facts 2006. A ferret has a longevity of around 9 years and 75 years. Use the model to predict the gestation period of a ferret.arrow_forward
- College AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning