Exam 11: Simple Linear Regression
Exam 1: Statistics, Data, and Statistical Thinking74 Questions
Exam 2: Methods for Describing Sets of Data188 Questions
Exam 3: Probability237 Questions
Exam 4: Random Variables and Probability Distributions273 Questions
Exam 5: Sampling Distributions52 Questions
Exam 6: Inferences Based on a Single Sample: Estimation With Confidence Intervals135 Questions
Exam 7: Inferences Based on a Single Sample: 355 Tests of Hypotheses144 Questions
Exam 8: Inferences Based on Two Samples: Confidence Intervals and Tests of Hypotheses102 Questions
Exam 9: Design of Experiments and Analysis of Variance87 Questions
Exam 10: Categorical Data Analysis59 Questions
Exam 11: Simple Linear Regression113 Questions
Exam 12: Multiple Regression and Model Building131 Questions
Exam 13: Methods for Quality Improvement: Statistical Process Control Available on CD89 Questions
Exam 14: Time Series: Descriptive Analyses, Models, and Forecasting Available on CD73 Questions
Exam 15: Nonparametric Statistics Available on CD49 Questions
Select questions type
(Situation P) Below are the results of a survey of America's best graduate and professional schools. The top 25 business schools, as determined by reputation, student selectivity, placement success, and graduation rate, are listed in the table.
For each school, three variables were measured: (1) GMAT score for the typical incoming student; (2) student acceptance rate (percentage accepted of all students who applied); and (3) starting salary of the typical graduating student. School GMAT Acc. Rate Salary 1. Harvard 644 15.0\% \ 63,000 2. Stanford 665 10.2 60,000 3. Penn 644 19.4 55,000 4. Northwestern 640 22.6 54,000 5. MIT 650 21.3 57,000 6. Chicago 632 30.0 55,269 7. Duke 630 18.2 53,300 8. Dartmouth 649 13.4 52,000 9. Virginia 630 23.0 55,269 10. Michigan 620 32.4 53.300 11. Columbia 635 37.1 52,000 12. Cornell 648 14.9 50,700 13. CMU 630 31.2 52,050 14. UNC 625 15.4 50,800 15. Cal-Berkeley 634 24.7 50,000 16. UCLA 640 20.7 51,494 17. Texas 612 28.1 43,985 18. Indiana 600 29.0 44,119 19. NYU 610 35.0 53,161 20. Purdue 595 26.8 43,500 21. USC 610 31.9 49,080 22. Pittsburgh 605 33.0 43,500 23. Georgetown 617 31.7 45,156 24. Maryland 593 28.1 42,925 25. Rochester 605 35.9 44,499 The academic advisor wants to predict the typical starting salary of a graduate at a top business school using GMAT score of the school as a predictor variable. A simple linear regression of SALARY versus GMAT using the 25 data points in the table are shown below.
-A 95% prediction interval for SALARY when GMAT = 600 is ($37,915, $51,948). Interpret this interval for the situation above.
(Multiple Choice)
5.0/5
(29)
a. Complete the table.
2 3 5 2 3 4 8 0 Totals \Sigma= \Sigma= \Sigma= \Sigma=
b. Find , and .
c. Write the equation of the least squares line.
(Essay)
4.8/5
(44)
A company keeps extensive records on its new salespeople on the premise that sales should increase with experience. A random sample of seven new salespeople produced the data on experience and sales shown in the table.
Months on Job Monthly Sales y (\ thousands) 2 2.4 4 7.0 8 11.3 12 15.0 1 .8 5 3.7 9 12.0
Summary statistics yield , and . Calculate a confidence interval for when months. Assume and the prediction equation is .
(Essay)
4.9/5
(38)
Suppose you fit a least squares line to 23 data points and the calculated value of SSE is .
a. Find , the estimator of .
b. What is the largest deviation you might expect between any one of the 23 points and the least squares line?
(Essay)
4.9/5
(39)
Consider the data set shown below. Find the standard deviation of the least squares regression line. 0 3 2 3 8 10 11 -2 0 2 4 6 8 10
(Multiple Choice)
4.8/5
(40)
A realtor collected the following data for a random sample of ten homes that recently sold in her area.
House Asking Price Days on Market A \ 114,500 29 B \ 149,900 16 C \ 154,700 59 D \ 159,900 42 E \ 160,000 72 F \ 165,900 45 G \ 169,700 12 H \ 171,900 39 I \ 175,000 81 J \ 289,900 121 a. Find a 90% confidence interval for the mean number of days on the market for all
houses listed at $150,000.
b. Suppose a house has just been listed at $150,000. Find a 90% prediction interval for the
number of days the house will be on the market before it sells.
(Essay)
4.7/5
(42)
The dean of the Business School at a small Florida college wishes to determine whether the grade-point average (GPA) of a graduating student can be used to predict the graduate's starting salary. More specifically, the dean wants to know whether higher GPAs lead to higher starting salaries. Records for 23 of last year's Business School graduates are selected at random, and data on GPA and starting salary , in \$thousands) for each graduate were used to fit the model
The value of the test statistic for testing is 17.169. Select the proper conclusion.
(Multiple Choice)
5.0/5
(45)
What is the relationship between diamond price and carat size? 307 diamonds were sampled and a straight-line relationship was hypothesized between y = diamond price (in dollars) and x = size of the diamond (in carats). The simple linear regression for the analysis is shown below: Least Squares Linear Regression of PRICE
Predictor Variables Coefficient Std Error T P Constant -2298.36 158.531 -14.50 0.0000 Size 11598.9 230.111 50.41 0.0000
R-Squared 0.8925 Resid. Mean Square (MSE) 1248950 Adjusted R-Squared 0.8922 Standard Deviation 1117.56
The model was then used to create 95% confidence and prediction intervals for y and for E(Y) when the carat size of the diamond was 1 carat. The results are shown here:
95% confidence interval for E(Y): ($9091.60, $9509.40)
95% prediction interval for Y: ($7091.50, $11,510.00)
Which of the following interpretations is correct if you want to use the model to estimate E(Y) for all 1-carat diamonds?
(Multiple Choice)
4.9/5
(38)
(Situation P) Below are the results of a survey of America's best graduate and professional schools. The top 25 business schools, as determined by reputation, student selectivity, placement success, and graduation rate, are listed in the table.
For each school, three variables were measured: (1) GMAT score for the typical incoming student; (2) student acceptance rate (percentage accepted of all students who applied); and (3) starting salary of the typical graduating student.
School GMAT Acc. Rate Salary 1. Harvard 644 15.0\% \ 63,000 2. Stanford 665 10.2 60,000 3. Penn 644 19.4 55,000 4. Northwestern 640 22.6 54,000 5. MIT 650 21.3 57,000 6. Chicago 632 30.0 55,269 7. Duke 630 18.2 53,300 8. Dartmouth 649 13.4 52,000 9. Virginia 630 23.0 55,269 10. Michigan 620 32.4 53.300 11. Columbia 635 37.1 52,000 12. Cornell 648 14.9 50,700 13. CMU 630 31.2 52,050 14. UNC 625 15.4 50,800 15. Cal-Berkeley 634 24.7 50,000 16. UCLA 640 20.7 51,494 17. Texas 612 28.1 43,985 18. Indiana 600 29.0 44,119 19. NYU 610 35.0 53,161 20. Purdue 595 26.8 43,500 21. USC 610 31.9 49,080 22. Pittsburgh 605 33.0 43,500 23. Georgetown 617 31.7 45,156 24. Maryland 593 28.1 42,925 25. Rochester 605 35.9 44,499
The academic advisor wants to predict the typical starting salary of a graduate at a top business school using GMAT score of the school as a predictor variable. A simple linear regression of SALARY versus GMAT using the 25 data points in the table are shown below.
-For the situation above, give a practical interpretation of .
(Multiple Choice)
4.8/5
(33)
A county real estate appraiser wants to develop a statistical model to predict the appraised value of houses in a section of the county called East Meadow. One of the many variables thought to be an important predictor of appraised value is the number of rooms in the house. Consequently, the appraiser decided to fit the simple linear regression model:
where appraised value of the house (in thousands of dollars) and number of rooms. Using data collected for a sample of houses in East Meadow, the following results were obtained:
Give a practical interpretation of the estimate of ?, the standard deviation of the random error term in the model.
(Multiple Choice)
4.9/5
(34)
A large national bank charges local companies for using its services. A bank official reported the results of a regression analysis designed to predict the bank's charges (y), measured in dollars per month, for services rendered to local companies. One independent variable used to predict the service charge to a company is the company's sales revenue , measured in \$ million. Data for 21 companies who use the bank's services were used to fit the model
The results of the simple linear regression are provided below.
Interpret the estimate of , the -intercept of the line.
(Multiple Choice)
4.8/5
(30)
What is the relationship between diamond price and carat size? 307 diamonds were sampled and a straight-line relationship was hypothesized between diamond price (in dollars) and size of the diamond (in carats). The simple linear regression for the analysis is shown below:
Least Squares Linear Regression of PRICE
Predictor Variables Coefficient Std Error T P Constant -2298.36 158.531 -14.50 0.0000 Size 11598.9 230.111 50.41 0.0000
R-Squared 0.8925 Resid. Mean Square (MSE) 1248950 Adjusted R-Squared 0.8922 Standard Deviation 1117.56
The model was then used to create 95% confidence and prediction intervals for y and for E(Y) when the carat size of the diamond was 1 carat. The results are shown here:
95% confidence interval for E(Y): ($9091.60, $9509.40)
95% prediction interval for Y: ($7091.50, $11,510.00)
Which of the following interpretations is correct if you want to use the model to determine the price of a single 1-carat diamond?
(Multiple Choice)
4.9/5
(48)
The Method of Least Squares specifies that the regression line has an average error of 0 and has an SSE that is minimized.
(True/False)
4.8/5
(35)
A county real estate appraiser wants to develop a statistical model to predict the appraised value of houses in a section of the county called East Meadow. One of the many variables thought to be an important predictor of appraised value is the number of rooms in the house. Consequently, the appraiser decided to fit the simple linear regression model:
where appraised value of the house (in thousands of dollars) and number of rooms.
What set of hypotheses would you test to determine whether appraised value is positively linearly related to number of rooms?
(Multiple Choice)
5.0/5
(37)
What is the relationship between diamond price and carat size? 307 diamonds were sampled (ranging in size from to carats) and a straight-line relationship was hypothesized between diamond price (in dollars) and size of the diamond (in carats). The simple linear regression for the analysis is shown below:
Least Squares Linear Regression of PRICE
Predictor Variables Coefficient Std Error T P Constant -2298.36 158.531 -14.50 0.0000 Size 11598.9 230.111 50.41 0.0000
R-Squared 0.8925 Resid. Mean Square (MSE) 1248950 Adiusted R-Souared 08920 Standard Deviation 111756
Interpret the estimated y-intercept of the regression line.
(Multiple Choice)
4.7/5
(36)
To investigate the relationship between yield of potatoes, y, and level of fertilizer application, x, a researcher divides a field into eight plots of equal size and applies differing amounts of fertilizer to each. The yield of potatoes (in pounds) and the fertilizer application (in pounds) are recorded for each plot. The data are as follows: x 1 1.5 2 2.5 3 3.5 4 4.5 y 25 31 27 28 36 35 32 34
Summary statistics yield , and . Calculate the coefficient of determination.
(Essay)
4.8/5
(36)
Consider the data set shown below. Find the coefficient of determination for the simple linear regression model. 0 3 2 3 8 10 11 -2 0 2 4 6 8 10
(Multiple Choice)
4.8/5
(37)
A company keeps extensive records on its new salespeople on the premise that sales should increase with experience. A random sample of seven new salespeople produced the data on experience and sales shown in the table.
Months on Job Monthly Sales y (\ thousands) 2 2.4 4 7.0 8 11.3 12 15.0 1 .8 5 3.7 9 12.0
Summary statistics yield , and . Using SSE , find and interpret the coefficient of determination.
(Essay)
4.8/5
(32)
Showing 21 - 40 of 113
Filters
- Essay(0)
- Multiple Choice(0)
- Short Answer(0)
- True False(0)
- Matching(0)