### Question Description

# Week 7 Assignment

Question

Assume you have noted the following prices for paperback books and the number of pages that each book contains.

Book | Pages (x variable) | Price (y variable) |

A | 510 | $7.50 |

B | 624 | $8.25 |

C | 557 | $7.75 |

D | 650 | $8.50 |

E | 532 | $7.65 |

F | 600 | $8.00 |

G | 472 | $6.75 |

- Create a scatter diagram with a regression line. Include the coefficient of determination on the graph. Hint: You can create the graph by putting the table into Excel, using the Insert function and selecting scatter diagram. Once the scatter diagram is in Excel, a green plus sign appears near the upper right corner. Click on it. The last option is trendline. Click that option. Then use the black triangle in that box to open more options which allow you to place the r squared value and the equation on the graph. Also remember from Week 1 all the things that a good graph needs
- Compute the Pearsons Product Moment Correlation Coefficient from your coefficient of determination. Does it indicate a strong positive relationship, a strong negative relationship, a weak positive relationship, a weak negative relationship, or no relationship?
- According to the trendline / regression line, if there were 592 pages, how much should the book cost? Show your work.
- According to the trendline/regression line, if there were 1976 pages, how much should the book cost? Show your work.
- According to the trendline/regression line, if the book cost $17.50, how many pages should it have had? Show your work.
- Given our discussion about the 130-inch tall person, which answer (#3 or #4) do you believe is more likely to be reliable? Why?
- Use the steps in the video lecture of the week to conduct a full hypothesis test with Excel doing the calculations to see if x and y are related. Use ? = 0.10 and the p-value method. Upload the Excel sheet in addition to the MS Word document. Remember from Week 6 that hypothesis testing is a series of steps. All steps are needed.

# Project Week 7

For these project assignments throughout the course you will need to reference the data in the ROI Excel spreadheet. Download it here.

For EACH of the two majors:

- Draw the scatter diagram of Y = Annual % ROI against X = Cost. Please double check that you have the right x and y variables. This is a crash and burn moment if you have them backwards. Make sure the regression line (trendline) is on the graph (see directions in the assignment). In addition, make sure the coefficient of determination is on the graph. Is your graph titled and labeled appropriately?
- Calculate the estimated Annual % ROI when the Cost (X) is $165,000. Show your work.
- If the Annual % ROI is 8.5%, what should the cost be?
- Conduct a full hypothesis test (all steps) in the p-value method and using Excel to do the calculations (as demonstrated in the video lecture). Set alpha at 0.05. Test the hypothesis:
- H0: ?1 = 0
- Ha: ?1 ? 0

- In a highlighted box, discuss your final conclusion from this hypothesis test. For each major, is Annual % ROI related to Cost for business? For engineering? If so, describe the relationship in words. Is it strong? Weak? positive? negative? How does the outcome of this hypothesis test related to the central question of which ROI is better? Remember that written portions should go on MS Word documents.

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