Chapter 13: Problem 4
Explain the difference between linear and nonlinear relationships between two variables.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 13: Problem 4
Explain the difference between linear and nonlinear relationships between two variables.
All the tools & learning materials you need for study success - in one app.
Get started for free
Explain the difference between a simple and a multiple regression model.
Two variables \(x\) and \(y\) have a negative linear relationship. Explain what happens to the value of \(y\) when \(x\) increases.
The following table, reproduced from Exercise \(13.26\), gives information on the amount of sugar (in grams) and the calorie count in one serving of a sample of 13 varieties of Kellogg's cereal. $$ \begin{array}{l|rrrrrrrrrrrrr} \hline \text { Sugar (grams) } & 4 & 15 & 12 & 11 & 8 & 6 & 7 & 2 & 7 & 14 & 20 & 3 & 13 \\ \hline \text { Calories } & 120 & 200 & 140 & 110 & 120 & 80 & 190 & 100 & 120 & 190 & 190 & 110 & 120 \\ \hline \end{array} $$ a. Determine the standard deviation of errors. b. Find the coefficient of determination and give a brief interpretation of it.
Suppose that you work part-time at a bowling alley that is open daily from noon to midnight. Although business is usually slow from noon to 6 P.M., the owner has noticed that it is better on hotter days during the summer, perhaps because the premises are comfortably air-conditioned. The owner shows you some data that she gathered last summer. This data set includes the maximum temperature and the number of lines bowled between noon and 6 P.M. for each of 20 days. (The maximum temperatures ranged from \(77^{\circ} \mathrm{F}\) to \(95^{\circ} \mathrm{F}\) during this period.) The owner would like to know if she can estimate tomorrow's business from noon to 6 P.M. by looking at tomorrow's weather forecast. She asks you to analyze the data. Let \(x\) be the maximum temperature for a day and \(y\) the number of lines bowled between noon and 6 P.M. on that day. The computer output based on the data for 20 days provided the following results: \(\hat{y}=-432+7.7 x, \quad s_{e}=28.17, \quad \mathrm{SS}_{x x}=607, \quad\) and \(\quad \bar{x}=87.5\) Assume that the weather forecasts are reasonably accurate. a. Does the maximum temperature seem to be a useful predictor of bowling activity between noon and 6 P.M.? Use an appropriate statistical procedure based on the information given. Use \(\alpha=.05\) b. The owner wants to know how many lines of bowling she can expect, on average, for days with a maximum temperature of \(90^{\circ}\). Answer using a \(95 \%\) confidence level. c. The owner has seen tomorrow's weather forecast, which predicts a high of \(90^{\circ} \mathrm{F}\). About how many lines of bowling can she expect? Answer using a \(95 \%\) confidence level. d. Give a brief commonsense explanation to the owner for the difference in the interval estimates of parts \(\mathrm{b}\) and \(\mathrm{c}\). e. The owner asks you how many lines of bowling she could expect if the high temperature were \(100^{\circ} \mathrm{F}\). Give a point estimate, together with an appropriate warning to the owner.
The following information is obtained for a sample of 80 observations taken from a population. $$ \mathrm{SS}_{x x}=380.592, \quad s_{e}=.961, \text { and } \hat{y}=160.24-2.70 x $$ a. Make a \(97 \%\) confidence interval for \(B\). b. Test at the \(1 \%\) significance level whether \(B\) is negative. c. Can you conclude that \(B\) is different from zero? Use \(\alpha=.01\). d. Using a significance level of 02, test whether \(B\) is less than \(-1,25\).
What do you think about this solution?
We value your feedback to improve our textbook solutions.