Week 8 Class Assignment

1 / 1 point Use the data below (ie. Copy and Paste into an Excel spreadsheet) to calculate a linear regression using Advertising (in Thousands of Dollars) as the X variable, and Sales (also in Thousands of Dollars) at the Y variable. What is the value of the slope of your linear regression? State your answer accurate to 4 decimal places. Adversiting ($ks) Sales ($ks) 366 10541 377 8991 387 5905 418 8251 434 11461 450 6924 457 7347 466 10972 467 7811 468 10559 468 9825 475 9130 479 5116 479 7830 481 8388 490 8588 494 6945 502 7697 505 9655 529 11516 532 11952 533 13547 542 9168 544 11942 547 9917 554 10666 556 9717 560 13457 561 10319 566 9731 566 10279 582 7202 609 12103 612 11482 617 11944

623 9188 Answer: 12.8669 Question 2 1 / 1 point Use the data below (ie. Copy and Paste into an Excel spreadsheet) to calculate a linear regression using Advertising (in Thousands of Dollars) as the X variable, and Sales (also in Thousands of Dollars) at the Y variable. What is the value of the Y-intercept of your linear regression? State your answer accurate to 4 decimal places. Adversiting ($ks) Sales ($ks) 366 10541 377 8991 387 5905 418 8251 434 11461 450 6924 457 7347 466 10972 467 7811 468 10559 468 9825 475 9130 479 5116 479 7830 481 8388 490 8588 494 6945 502 7697 505 9655 529 11516 532 11952 533 13547 542 9168 544 11942 547 9917 554 10666 556 9717 560 13457 561 10319 566 9731

547 9917 554 10666 556 9717 560 13457 561 10319 566 9731 566 10279 582 7202 609 12103 612 11482 617 11944 623 9188 Answer: 0.1796 Question 4 1 / 1 point The following table represents data collected from 20 promotions used to sell a laptop. Data from three independent variables (Advertising Budget in thousands of dollars, X1, Price of the laptop, X2, and Price of the Competitor's laptop, X3) was recorded for each promotion along with the resulting sales, also in thousands of dollars. Use this data to construct a linear regression model. Use your model to predict E(Y/X1=387,X2=93.30,X3=93.85), accurate to 4 decimal places. Promotion Adversiting ($ks) Price ($) Competition Price ($) Sales ($ks) 1 366 90.99 96.95 10541 2 377 90.99 93.99 8991 3 387 94.99 90.99 5905 4 418 96.99 97.95 8251 5 434 92.99 97.95 11461 6 450 95.95 93.95 6924 7 457 93.95 90.99 7347 8 466 91.95 96.95 10972 9 467 96.95 94.99 7811 10 468 92.95 96.95 10559 11 468 97.99 98.95 9825 12 475 91.95 90.99 9130 13 479 99.95 91.95 5116 14 479 96.99 95.95 7830 15 481 91.95 90.95 8388 16 490 96.99 96.99 8588

17 494 96.95 91.95 6945 18 502 98.95 95.95 7697 19 505 94.99 96.99 9655 20 529 93.99 97.95 11516 Answer: 8091.261 9 Question 5 0 / 1 point What differences do you see between the linear regression formed using two random variables and that formed using many random variables?