
Concept explainers
(a)
Section 1:
To find: The difference between the TBBMC recorded for Operator 1 and the TBBMC for Operator 2.
(a)
Section 1:

Answer to Problem 43E
Solution: The table for difference is as follows:
Operator 1 |
Operator 2 |
Difference |
1.328 |
1.323 |
0.005 |
1.342 |
1.322 |
0.02 |
1.075 |
1.073 |
0.002 |
1.228 |
1.233 |
−0.005 |
0.939 |
0.934 |
0.005 |
1.004 |
1.019 |
−0.015 |
1.178 |
1.184 |
−0.006 |
1.286 |
1.304 |
−0.018 |
Explanation of Solution
Calculation:
To calculate the difference, follow the below mentioned steps in Minitab:
Step 1: Enter the variable name as “Operator 1” in column C1 and enter the data for “Operator 1” and enter the variable name as “Operator 2” in column C2 and enter the data for “Operator 2.”
Step 2: Enter variable name as “Difference” in column C3.
Step 3: Go to
Step 4: In the dialog box that appears, select “Difference” in “Store result in variable.”
Step 5: Enter “Operator 1”-“Operator 2” in “Expression.” Click on “Ok” on the dialog box.
From Minitab result, the table for difference is as follows:
Operator 1 |
Operator 2 |
Difference |
1.328 |
1.323 |
0.005 |
1.342 |
1.322 |
0.02 |
1.075 |
1.073 |
0.002 |
1.228 |
1.233 |
−0.005 |
0.939 |
0.934 |
0.005 |
1.004 |
1.019 |
−0.015 |
1.178 |
1.184 |
−0.006 |
1.286 |
1.304 |
−0.018 |
Interpretation: It is clear from the table that the
Section 2:
To test: Whether t- methods can be used or not.
Section 2:

Answer to Problem 43E
Solution: The t- method can be used.
Explanation of Solution
Calculation:
To determine if the t methods can be used or not, a probability plot is drawn in Minitab by following the below mentioned steps:
Step 1: Follow steps 1 and 2 similar to that in Section 1.
Step 2: Go to “Graph” option and click on “Probability Plot.” In the dialog box that appears, select “Single” and click on OK.
Step 3: Then enter the name of the column containing the data of the differences in the “Graph variables” field and click on OK.
The following probability plot is obtained:
Conclusion: The probability plot shows that the data is approximately normal as all the data points fall within the range and, hence, it is appropriate to use t procedures.
(b)
To test: The significance of the difference between the means of two operators.
(b)

Answer to Problem 43E
Solution: The test statistic value is
Explanation of Solution
Calculation:
To test the null hypothesis, follow the below mentioned steps in Minitab:
Step 1: Follow the Steps 1 to 5 performed in section 1 of part (a).
Step 2: Go to
Step 3: In the dialogue box that appears, select samples in columns.
Step 4: Enter “Operator 1” under the field marked as “First sample” and “Operator 2” under the field marked as “Second sample.”
Step 5: In the dialogue box that appears, Click on “Option.” Enter 95.0 in the field of Confidence interval, 0.0 in “Test mean,” and “not equal” in “Alternative.”
From Minitab results, the value of test statistic is
D.F = n –.
D.F = 8 –.
D.F =.
Conclusion: If the level of significance is 5% then as the p- value is greater than 0.05 the null hypothesis will not be rejected and it is concluded that the two means do not differ significantly at 95% confidence level.
(c)
To find: The confidence interval for difference.
(c)

Answer to Problem 43E
Solution: The required confidence interval is
Explanation of Solution
Calculation: To compute the confidence interval, follow the below mentioned steps in Minitab:
Step 1: Follow the steps 1 to 5 performed in section 1 of part (a).
Step 2: Go to
Step 3: In the dialogue box that appears, select samples in columns.
Step 4: Enter “Operator 1” under the field marked as “First sample” and “Operator 2” under the field marked as “Second sample.”
Step 5: In the dialogue box that appears, Click on “Option.” Enter 95.0 in the field of Confidence interval, 0.0 in “Test mean,” and “not equal” in “Alternative.”
From the Minitab results, the confidence interval is
Interpretation: The confidence interval denotes that the differences recorded will lie in between −0.01172 and 0.00872 with a possible chance of 5% error.
(d)
The validity of the results if the samples are not random.
(d)

Answer to Problem 43E
Solution: The testing results and the confidence interval may not be valid if the samples are non-random.
Explanation of Solution
Want to see more full solutions like this?
Chapter 7 Solutions
LaunchPad for Moore's Introduction to the Practice of Statistics (12 month access)
- Suppose you are gambling on a roulette wheel. Each time the wheel is spun, the result is one of the outcomes 0, 1, and so on through 36. Of these outcomes, 18 are red, 18 are black, and 1 is green. On each spin you bet $5 that a red outcome will occur and $1 that the green outcome will occur. If red occurs, you win a net $4. (You win $10 from red and nothing from green.) If green occurs, you win a net $24. (You win $30 from green and nothing from red.) If black occurs, you lose everything you bet for a loss of $6. a. Use simulation to generate 1,000 plays from this strategy. Each play should indicate the net amount won or lost. Then, based on these outcomes, calculate a 95% confidence interval for the total net amount won or lost from 1,000 plays of the game. (Round your answers to two decimal places and if your answer is negative value, enter "minus" sign.) I worked out the Upper Limit, but I can't seem to arrive at the correct answer for the Lower Limit. What is the Lower Limit?…arrow_forwardLet us suppose we have some article reported on a study of potential sources of injury to equine veterinarians conducted at a university veterinary hospital. Forces on the hand were measured for several common activities that veterinarians engage in when examining or treating horses. We will consider the forces on the hands for two tasks, lifting and using ultrasound. Assume that both sample sizes are 6, the sample mean force for lifting was 6.2 pounds with standard deviation 1.5 pounds, and the sample mean force for using ultrasound was 6.4 pounds with standard deviation 0.3 pounds. Assume that the standard deviations are known. Suppose that you wanted to detect a true difference in mean force of 0.25 pounds on the hands for these two activities. Under the null hypothesis, 40 0. What level of type II error would you recommend here? = Round your answer to four decimal places (e.g. 98.7654). Use α = 0.05. β = 0.0594 What sample size would be required? Assume the sample sizes are to be…arrow_forwardConsider the hypothesis test Ho: 0 s² = = 4.5; s² = 2.3. Use a = 0.01. = σ against H₁: 6 > σ2. Suppose that the sample sizes are n₁ = 20 and 2 = 8, and that (a) Test the hypothesis. Round your answers to two decimal places (e.g. 98.76). The test statistic is fo = 1.96 The critical value is f = 6.18 Conclusion: fail to reject the null hypothesis at a = 0.01. (b) Construct the confidence interval on 02/2/622 which can be used to test the hypothesis: (Round your answer to two decimal places (e.g. 98.76).) 035arrow_forward
- Using the method of sections need help solving this please explain im stuckarrow_forwardPlease solve 6.31 by using the method of sections im stuck and need explanationarrow_forwarda) When two variables are correlated, can the researcher be sure that one variable causes the other? If YES , why? If NO , why? b) What is meant by the statement that two variables are related? Discuss.arrow_forward
- SCIE 211 Lab 3: Graphing and DataWorksheetPre-lab Questions:1. When should you use each of the following types of graphs? Fill answers in the table below.Type of Graph Used to showLine graphScatter plotBar graphHistogramPie Chart2. Several ways in which we can be fooled or misled by a graph were identified in the Lab 3Introduction. Find two examples of misleading graphs on the Internet and paste them below. Besure to identify why each graph is misleading. Data Charts:Circumference vs. Diameter for circular objectsDiameter Can 1 (cm) Can 2 (cm) Can 3 (cm)Trial 1Trial 2Trial 3MeanCircumference Can 1 (cm) Can 2 (cm) Can 3 (cm)Trial 1Trial 2Trial 3MeanScatter Plot Graph – Circumference Vs. DiameterIdentify 2 points of the Trendline.Y1 = ________ Y2 = _________X1 = ________ X2 = _________Calculate the Slope of the Trendline = Post-lab Questions:1. Answer the questions below. You will need to use the following equation to answer…arrow_forwardThe U.S. Bureau of Labor Statistics reports that 11.3% of U.S. workers belong to unions (BLS website, January 2014). Suppose a sample of 400 U.S. workers is collected in 2014 to determine whether union efforts to organize have increased union membership. a. Formulate the hypotheses that can be used to determine whether union membership increased in 2014.H 0: p H a: p b. If the sample results show that 52 of the workers belonged to unions, what is the p-value for your hypothesis test (to 4 decimals)?arrow_forwardA company manages an electronic equipment store and has ordered 200200 LCD TVs for a special sale. The list price for each TV is $200200 with a trade discount series of 6 divided by 10 divided by 2.6/10/2. Find the net price of the order by using the net decimal equivalent.arrow_forward
- According to flightstats.com, American Airlines flights from Dallas to Chicago are on time 80% of the time. Suppose 10 flights are randomly selected, and the number of on-time flights is recorded. (a) Explain why this is a binomial experiment. (b) Determine the values of n and p. (c) Find and interpret the probability that exactly 6 flights are on time. (d) Find and interpret the probability that fewer than 6 flights are on time. (e) Find and interpret the probability that at least 6 flights are on time. (f) Find and interpret the probability that between 4 and 6 flights, inclusive, are on time.arrow_forwardShow how you get critical values of 1.65, -1.65, and $1.96 for a right-tailed, left- tailed, and two-tailed hypothesis test (use a = 0.05 and assume a large sample size).arrow_forwardSuppose that a sports reporter claims the average football game lasts 3 hours, and you believe it's more than that. Your random sample of 35 games has an average time of 3.25 hours. Assume that the population standard deviation is 1 hour. Use a = 0.05. What do you conclude?arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman





