Quantitative Analysis for Busines
BUSA 3000: Quantitative Analysis for Business
Topic #5 Problem Set
Directions: Submit your final answers using D2L Quizzes.
- Many countries, especially those in Europe, still have significant gold holdings. Many of these countries also have a large amount of debt. The following is a data set of those two variables for a select number of nations in 2012, alongside the country names. Data come from the websites WordPress and Trading Economics.
| Country | Gold value ($ billions) | Debt (% of GDP) |
| China | 63 | 17.7 |
| France | 146 | 81.7 |
| Germany | 203 | 83.2 |
| Indonesia | 33 | 69.2 |
| Italy | 147 | 119.0 |
| The Netherlands | 36 | 63.7 |
| Russia | 50 | 9.9 |
| Switzerland | 62 | 55.0 |
| United States | 487 | 93.2 |
- Develop a regression equation for the impact of gold holdings on debt. What is ?
- What is ?
- Estimate the debt of a country with a gold value of $100 billion.
- Create a scatterplot. Does it indicate a positive, negative, or null relationship?
- Calculate .
- Perform a significance test for . Is it significant at the 95% confidence level?
- The regional transit authority for Atlanta wants to determine if there is a relationship between the age of a bus and its annual maintenance cost. The following sample of 10 buses was collected in 2010 to answer this question.
| Bus number | Age (in years) | Cost ($) |
| 11 | 1 | 350 |
| 12 | 2 | 370 |
| 13 | 2 | 480 |
| 14 | 2 | 520 |
| 15 | 2 | 590 |
| 16 | 3 | 550 |
| 17 | 4 | 750 |
| 18 | 4 | 800 |
| 19 | 5 | 790 |
| 20 | 5 | 950 |
- Develop a regression for the impact of bus age on maintenance cost. What is ?
- What is ?
- Estimate the maintenance cost of a bus that is brand new (age = 0 years).
- Create a scatterplot. Does it indicate a positive, negative, or null relationship?
- Calculate .
- Perform a significance test for . Is it significant at the 95% confidence level?
- One of the biggest changes in higher education during the early 21st century was the rise of online schools. The following is a data set from 2009 on some online colleges in the U.S. The two variables shown are the school’s retention rate (the % of students who stayed enrolled from 2008 to 2009) and graduation rate (the % of students who typically graduate).
| College | Retention rate (%) | Graduation rate (%) |
| Western International University | 7 | 25 |
| South University | 51 | 25 |
| University of Phoenix | 4 | 28 |
| American InterContinential Univ. | 29 | 32 |
| Franklin University | 33 | 33 |
| DeVry University | 47 | 33 |
| Tiffin University | 63 | 34 |
| Post University | 45 | 36 |
| Peirce College | 60 | 36 |
| Everest University | 62 | 36 |
| Upper Iowa University | 67 | 36 |
| Dickinson State University | 65 | 37 |
| Western Governors University | 78 | 37 |
| Kaplan University | 75 | 38 |
| Salem International University | 54 | 39 |
| Ashford University | 45 | 41 |
| ITT Technical Institute | 38 | 44 |
| Berkeley College | 51 | 45 |
| Grand Canyon University | 69 | 46 |
| Nova Southeastern University | 60 | 47 |
| Westwood College | 37 | 48 |
| Everglades University | 63 | 50 |
| Liberty University | 73 | 51 |
| LeTourneau University | 78 | 52 |
| Rasmussen College | 48 | 53 |
| Keiser University | 95 | 55 |
| Herzing College | 68 | 56 |
| National University | 100 | 57 |
| Florida National College | 100 | 61 |
- Develop a regression for the impact of retention on graduation. What is ?
- What is ?
- Estimate the graduation rate of a college with a 50% retention rate.
- Create a scatterplot. Does it indicate a positive, negative, or null relationship?
- Calculate .
- Perform a significance test for . Is it significant at the 95% confidence level?
