
Twinned drill holes. Refer to the Exploration and Mining Geology (Vol. 18, 2009) study of drill twinned holes, Exercise 8.33 (p. 455). Recall that the drilling of a new hole, or “twin,” next to an earlier drill hole is a traditional method of verifying mineralization grades. The data in the next table represent total amount of heavy minerals (THM) percentages for a sample of 15 twinned holes drilled at a diamond mine in Africa. In Exercise 8.33 you used a confidence interval based on Student’s t-distribution to check for a difference in the true THM means of all original holes and their twin holes drilled at the mine.
- a. Explain why the results of the confidence interval may be invalid.
- b. What is the appropriate nonparametric test to apply? State H0andH2for the test.
- c. Compute the difference between the “1st hole” and “2nd hole” measurements for each drilling location.
- d. Rank the differences, part c.
- e. Compute the rank sums of the positive and negative differences.
- f. Use the rank sums, parte, to conduct the nonparametric test at α = .05. Can the geologists conclude that there is no evidence of a difference in the THM distributions of all original holes and their twin holes drilled at the mine?
Location | 1st Hole | 2nd Hole |
1 | 5.5 | 5.7 |
2 | 11.0 | 11.2 |
3 | 5.9 | 6.0 |
4 | 8.2 | 5.6 |
5 | 10.0 | 9.3 |
6 | 7.9 | 7.0 |
7 | 10.1 | 8.4 |
8 | 7.4 | 9.0 |
9 | 7.0 | 6.0 |
10 | 9.2 | 8.1 |
11 | 8.3 | 10.0 |
12 | 8.6 | 8.1 |
13 | 10.5 | 10.4 |
14 | 5.5 | 7.0 |
15 | 10.0 | 11.2 |
Source: Data from Exploration and Mining Geology, Vol. 18, 2009. |

Want to see the full answer?
Check out a sample textbook solution
Chapter 15 Solutions
MyLab Statistics for Business Stats with Pearson eText -- Standalone Access Card -- for Statistics for Business and Economics
- Suppose Person A is looking for a health insurance plan on Oregon's health insurance marketplace and they find one with the following details: Monthly Premium: $331 Deductible: $5,000 Primary care visit to treat injury or illness: $35 copay Imaging (CT/PET Scans MRIs): 40% coinsurance after deductible Ambulance: 40% coinsurance after deductible Inpatient hospital stay: 40% coinsurance after deductible Suppose further that Person A purchases this plan and it takes effect in January 2022. The cost Person A pays per month for this health insurance is equal to _. Person A must pay. before coinsurance kicks in. 0000 $35; $5,000 $35; $331 $331; $5,000 $331; $35 Multiple Choice 1 point Suppose Person A is looking for a health insurance plan on Oregon's health insurance marketplace and you find one with the following details: Monthly Premium: $331 Deductible: $5,000 Primary care visit to treat injury or illness: $35 copay Imaging (CT/PET Scans MRIs): 40% coinsurance after deductible Ambulance:…arrow_forwardUse the figure below to answer the following question. Point X and Y represent two non-ideal contracts that the individual is faced with buying. From this information, you can conclude that if given the option between points B and Y the individual would prefer: Utility A у в 0000 UKI) E[Bp IH point B- the actuarially fair and full contract point Y-the actuarially unfair but full contract point Y- the actuarially fair, but partial contract point B- the actuarially fair, but partial contract incomearrow_forward2. Another issue facing millennials is the growing income and wealth inequality. We will use our model to understand the implications of this issue. A. Begin from the baseline preferences and endowments. Assume Xavier is wealthier than Yuri. Xavier has an endowment of 1100 pounds for each period (E1=E2=1100). Yuri has an endowment of only 900 pounds in each period (E1=E2=900). Note that each period's market supply is unchanged (1100 + 900 = 1000 + 1000 = = 2000). Determine the equilibrium interest rate. r = % B. Begin from the baseline preferences and endowments. Assume Yuri is wealthier than Xavier. Xavier has an endowment of only 900 pounds in each period (E1=E2=900). Yuri has an endowment of 1100 pounds for each period (E1=E2=1100). Note that each period's market supply is unchanged (1100 + 900 = 1000 + 1000 = 2000). Determine the equilibrium interest rate. r = % C. Begin from the baseline preferences and endowments. A third person named Zena joins our economy. Zena is very…arrow_forward
- Use the figure below to answer the following question. Let I represent Income when health, let Is represent income when ill. Let E[I] represent expected income. Point D represents Utility 100000 B у いいつ income есва Ін Is the expected utility from income with no insurance an actuarially fair and partial contract an actuarially fair and full contract an actuarially unfair and full contract an actuarially unfair and partial contractarrow_forwardOutline the principles of opportunity cost and comparative advantage. Describe how these principles can be applied to address the scarcity of resources in a real-world scenario involving a company or industry.arrow_forwardNot use ai pleasearrow_forward
- 3. Consider the case of everyone being wealthier in the future, such as from a positive productivity shock (computers, internet, robotics, AI). A. Begin from the baseline preferences and endowments. Give both people an endowment of 1000 pounds for the first period and 1100 pounds for the second. AI increases the supply of second period goods by 10%. Note that there is now a total of 2000 pounds in the first period and 2200 pounds in the second. Determine the equilibrium interest rate. r = % B. Begin from the baseline preferences and endowments. Give both people an endowment of 1100 pounds for the first and 1100 pounds for the second periods. AI increases the supply in all periods by 10%. Note that there are now 2200 pounds in the first period and 2200 pounds in the second. Determine the equilibrium interest rate. r = % C. Explain how productivity and the real rate are connected. Write at least five sentences.arrow_forwardNot use ai pleasearrow_forwardNot use ai pleasearrow_forward
- Not use ai pleasearrow_forwardJim's Bank Account for the Year to 30 April 2008: We will start by calculating the balance of the business bank account, using the transactions provided. Opening Balance: Jim initially deposited €150,000 into his business bank account on 1 May 2007. Transactions: Receipts: Cash Sales (May 2007 to April 2008): €96,000 Credit Sales (Business customers): €19,600 (Note: This amount is not yet received as it is on credit, but it will be included in the Income Statement and not the bank balance at this stage.) Bank receipts from credit customers (amount owed at 30 April 2008): €6,800 Total Receipts:€96,000 (Cash Sales) + €6,800 (credit customer payments) = €102,800 Payments/Expenditures: Lease Payment (Paid in advance for five years): €50,000 Shop Fitting: €10,000 Assistant’s Wages: €250 per month × 12 months = €3,000 Telephone expenses: €800 Heat & Light expenses: €1,000 Jim’s withdrawals for personal expenditure: €1,000 × 12 months = €12,000 Accounting Fee (after the year-end):…arrow_forwardSolve the problemarrow_forward
- Managerial Economics: Applications, Strategies an...EconomicsISBN:9781305506381Author:James R. McGuigan, R. Charles Moyer, Frederick H.deB. HarrisPublisher:Cengage Learning




