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Ch. 9 - Correlation and Regression
Larson - Elementary Statistics: Picturing the World 8th Edition
Larson8th EditionElementary Statistics: Picturing the WorldISBN: 9780137493470당신이 사용하는 게 아니라요?교과서 변경
9장, 문제 9.T.1

"1. Net Sales The equation used to predict the net sales (in millions of dollars) for a fiscal
year for a clothing retailer is y=23,769 + 9.18x_1 - 8.41x_2
where x_1 is the number of stores open at the end of the fiscal year and x_2 is the average
square footage per store. Use the multiple regression equation to predict the y-values for
the values of the independent variables.
a. x_1 = 1057, x_2 = 3698
b. x_1 = 1012, x_2 = 3659
c. x_1 = 952, x_2 = 3601
d. x_1 = 914, x_2 = 3594"

검증된 단계별 안내
1
Identify the multiple regression equation given: y = 23769 + 9.18 x_1 - 8.41 x_2, where x_1 is the number of stores and x_2 is the average square footage per store.
For each set of values of x_1 and x_2, substitute these values into the regression equation. For example, for part (a), substitute x_1 = 1057 and x_2 = 3698.
Perform the multiplication for each term involving the independent variables: multiply 9.18 by x_1 and multiply -8.41 by x_2.
Add the constant term 23769 to the results of the multiplications to calculate the predicted net sales y for each case.
Repeat steps 2 to 4 for each set of values given in parts (b), (c), and (d) to find all predicted net sales values.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Multiple Linear Regression

Multiple linear regression models the relationship between one dependent variable and two or more independent variables. It estimates how changes in each independent variable affect the dependent variable, holding others constant. The equation y = b0 + b1x1 + b2x2 represents this, where coefficients quantify the impact of each predictor.
추천 영상:
가이드 코스
07:01
Intro to Least Squares Regression

Interpreting Regression Coefficients

Regression coefficients indicate the expected change in the dependent variable for a one-unit increase in an independent variable, assuming other variables remain fixed. For example, a coefficient of 9.18 for x1 means net sales increase by 9.18 million dollars per additional store, all else equal.
추천 영상:
가이드 코스
06:14
Coefficient of Determination

Prediction Using Regression Equations

Prediction involves substituting given values of independent variables into the regression equation to calculate the estimated dependent variable. This process helps forecast outcomes, such as net sales, based on specific inputs like number of stores and average store size.
추천 영상:
가이드 코스
04:57
Using Regression Lines to Predict Values
관련 실천
교과서 질문

Writing Use an appropriate research source to find a real-life data set with the indicated cause-and-effect relationship. Write a paragraph describing each variable and explain why you think the variables have the indicated cause-and-effect relationship.

a. Direct Cause-and-Effect: Changes in one variable cause changes in the other variable.

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교과서 질문

"In Exercises 13-16, use the value of the correlation coefficient r to calculate the coefficient of determination r^2. What does this tell you about the explained variation of the data about the regression line? about the unexplained variation?

15. r = 0.642"

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교과서 질문

"[APPLET] For Exercises 2–9, use the data in the table, which shows the average annual salaries (both in thousands of dollars) for librarians and postsecondary library science teachers in the United States for 12 years. (Source: U.S. Bureau of Labor Statistics)

7. Find the coefficient of determination r^2 and interpret the result."

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교과서 질문

"[APPLET] For Exercises 2–9, use the data in the table, which shows the average annual salaries (both in thousands of dollars) for librarians and postsecondary library science teachers in the United States for 12 years. (Source: U.S. Bureau of Labor Statistics)

8. Find the standard error of estimate Se and interpret the result."

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교과서 질문

"The U.S. Food and Drug Administration (FDA) requires nutrition labeling for most foods. Un FDA regulations, manufacturers are required to list the amounts of certain nutrients in their foods, such as calories, sugar, fat, and carbohydrates. This nutritional information is displayed in the ""Nutrition Facts"" panel on the food's package.

The table shows the nutritional content below for one cup of each of 21 different breakfast

cereals.

C = calories

S = sugar in grams

F = fat in grams

R = carbohydrates in grams

7. Use the equations from Exercise 6 to predict the calories in 1 cup of cereal that has 7 grams of sugar, 0.5 gram of fat, and 31 grams of carbohydrates."

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교과서 질문

"[APPLET] For Exercises 2–9, use the data in the table, which shows the average annual salaries (both in thousands of dollars) for librarians and postsecondary library science teachers in the United States for 12 years. (Source: U.S. Bureau of Labor Statistics)

6. Use the regression equation that you found in Exercise 5 to predict the average annual salary of postsecondary library science teachers when the average annual salary of librarians is \$61,000."

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