
A random sample of 30 executives from companies with assets over $1 million was selected and asked for their annual income and level of education. The ANOVA comparing the average income among three levels of education rejected the null hypothesis. The
|
High School or less |
Undergraduate Degree |
Master's Degree or More |
Number Sampled |
7 |
11 |
12 |
Mean Salary (1,000s) |
49 |
76.3 |
78.3 |
a) When comparing the mean annual incomes for executives with undergraduate and master's degrees or more, which of the following 95% confidence interval can be constructed?
b) Based on the comparison between the mean annual incomes for executives with undergraduate and master's degrees or more, ________.

Trending nowThis is a popular solution!
Step by stepSolved in 2 steps

- A psychology student conducted a study on using a chief executive officer's facial structure to predict a firm's financial performance. The facial width-to-height ratio (WHR) for each in a sample of 47 CEOs at publicly traded firms was determined. The sample resulted in x=2.23 and s=0.35. The student wants to predict the financial performance of a firm based on the value of the true mean facial WHR of CEOs. The student wants to use the value of μ=2.1. Do you recommend he use this value? Conduct a test of hypothesis for μ to help you answer the question. Specify all the elements of the test, including H0, Ha, test statistic, p-value, and your conclusion. Test at α=0.01.arrow_forwardIn a study examining the relation of math ability to the belief that math ability was innate, the belief was considered the predictor variable. The researcher hopes to find a correlation between the participants’ math ability and their belief that math ability is innate. The scores for the three participants are shown below. The group that believed that math is NOT innate scored 66, 70, 50. The group that believed that math IS innate scored 7, 4,10. what are the mean and SD for each group?arrow_forwardAn adventure company runs two obstacle courses, Fundash and Coolsprint. The designer of the courses suspects that the mean completion time of Fundash is not equal to the mean completion time of Coolsprint. To test this, she selects 205 Fundash runners and 300 Coolsprint runners. (Consider these as random samples of the Fundash and Coolspring runners.) The 205 Fundash runners complete the course with a mean time of 76.7 minutes and a standard deviation of 5.3 minutes. The 300 Coolsprint runners complete the course with a mean time of 77.5 minutes and a standard deviation of 5.1 minutes. Assume that the population standard deviations of the completion times can be estimated to be the sample standard deviations, since the samples that are used to compute them are quite large. At the 0.05 level of significance, is there enough evidence to support the claim that the mean completion time, ,, of Fundash is not equal to the mean completion time, μ₂, of Coolsprint? Perform a two-tailed test.…arrow_forward
- Previously, an organization reported that teenagers spend 8.5 hours per week, on average, on the phone. The organization thinks that, currently, the mean is higher. Twenty-three randomly chosen teenagers were asked how many hours per week they spend on the phone, with the following results (in hours): 8.3, 8.5, 10.5, 2.9, 6.7, 7.7, 13.8, 7.8, 8.7, 11.8, 12, 6.1, 5.4, 5.8, 8.5, 7.9, 10.1,11.1, 11.6, 12.9, 3.6, 6.4, 11.2 Perform a hypothesis test using a 3% level of significance. Step 1: State the null and alternative hypotheses. Ho: ??v H: ? v ? v (So we will be performing a Select an answer v test.) Step 2: Assuming the null hypothesis is true, determine the features of the distribution of point estimates using the Central Limit Theorem. v with By the Central Limit Theorem, we know that the point estimates are Select an answer and distribution standard deviation distribution mean Step 3: Find the p-value of the point estimate. P? v? v = P(| ? ♥| ? varrow_forwardA hypertension trial is mounted and 12 participants are randomly assigned to receive either a new treatment or a placebo. Each participant takes the assigned medication and their systolic blood pressure (SBP) is recorded after 6 months on the assigned treatment. The data are as follows. Placebo New Treatment 132 114 143 119 148 121 144 124 155 126 160 128 Is there a difference in mean SBP between treatments? Run the test at a 5% level of significance. Give each of the following to receive full credit : 1) the appropriate null and alternative hypotheses; 2) the appropriate test; 3) the decision rule; 4) the calculation of the test statistic ; and 5) your conclusion including a comparison to alpha or the critical value. You MUST show your work to receive full credit. Partial credit is available.arrow_forwardAn adventure company runs two obstacle courses, Fundash and Coolsprint. The designer of the courses suspects that the mean completion time of Fundash is not equal to the mean completion time of Coolsprint. To test this, she selects 250 Fundash runners and 285 Coolsprint runners. (Consider these as random samples of the Fundash and Coolspring runners.) The 250 Fundash runners complete the course with a mean time of 76.7 minutes and a standard deviation of 5.7 minutes. The 285 Coolsprint runners complete the course with a mean time of 77.5 minutes and a standard deviation of 5.6 minutes. Assume that the population standard deviations of the completion times can be estimated to be the sample standard deviations, since the samples that are used to compute them are quite large. At the 0.05 level of significance, is there enough evidence to support the claim that the mean completion time, u, of Fundash is not equal to the mean completion time, µa, of Coolsprint? Perform a two-tailed test.…arrow_forward
- A magazine reports that women trust recommendations from a particular social networking site more than recommendations from any other social network platform. But does trust in this social networking site differ by gender? The following sample data show the number of women and men who stated in a recent sample that they trust recommendations made on this particular social networking site. Women Men Sample 150 170 Trust RecommendationsMade on the social networking site 117 102 (a) What is the point estimate of the proportion of women who trust recommendations made on this particular social networking site? (b) What is the point estimate of the proportion of men who trust recommendations made on this particular social networking site? (c) Provide a 95% confidence interval estimate of the difference between the proportion of women and men who trust recommendations made on this particular social networking site. (Round your answers to four decimal places.) toarrow_forwardSuppose the mean price for used cars is $10,198. A manager of a Kansas City used car dealership reviewed a sample of 50 recent used car sales at the dealership in an attempt to determine whether the population mean price for used cars at this particular dealership differed from the national mean. The prices for the sample of 50 cars are shown in the file named UsedCars. 12,400 10,400 12,100 10,000 11,000 8,895 7,675 9,975 6,350 10,470 9,895 11,250 8,795 12,500 9,340 10,150 9,200 9,395 11,000 10,640 10,000 7,500 8,000 10,440 10,200 10,300 9,740 9,280 10,930 8,000 9,000 7,680 9,400 10,730 7,350 12,240 11,970 8,240 9,910 10,080 9,440 8,970 9,500 10,050 10,130 11,400 8,500 7,500 9,090 10,500 (a) Formulate the hypotheses that can be used to determine whether a difference exists in the mean price for used cars at the dealership. H0: ? ≤ 10,198 Ha: ? > 10,198 H0: ? < 10,198 Ha: ? ≥ 10,198 H0: ? = 10,198 Ha: ? ≠ 10,198 H0: ? > 10,198 Ha: ? ≤ 10,198 H0: ? ≥ 10,198…arrow_forwardThe work week for adults in the US that work full time is normally distributed with a mean of 47 hours. A newly hired engineer at a start-up company believes that employees at start-up companies work more on average then most working adults in the US. She asks 12 engineering friends at start-ups for the lengths in hours of their work week. Their responses are shown in the table below. Test the claim using a 10% level of significance. Hours 47 47 55 51 48 65 51 52 50 49 51 54 What are the correct hypotheses? Ho: Select an answer ✓ ? ✓ Ha: Select an answer ✓ Test Statistic= hours Based on the hypotheses, find the following: p-value= hours (Give answer to at least 4 decimal places.) (Give answer to at least 4 decimal places).arrow_forward
- A recent article in the Journal of Urban Chicken Farmers reported the fraction of chickens that experience severe, moderate, or minor side effects from a new diet are 0.07, 0.15, and 0.78 respectively. Assuming that chickens respond independently, if 18 chickens were tested on the new diet, what is the: 3. a. Mean number of chickens that will suffer severe side effects? b. Variance in the number of chickens that will suffer severe side effects? C.Conditional mean of the number of chickens that suffer severe side effects given that 17 suffer minor side effects.arrow_forwardAn adventure company runs two obstacle courses, Fundash and Coolsprint. The designer of the courses suspects that the mean completion time of Fundash is not equal to the mean completion time of Coolsprint. To test this, she selects 240 Fundash runners and 200 Coolsprint runners. (Consider these as random samples of the Fundash and Coolspring runners.) The 240 Fundash runners complete the course with a mean time of 76.7 minutes and a standard deviation of 5.2 minutes. The 200 Coolsprint runners complete the course with a mean time of 77.5 minutes and a standard deviation of 5.4 minutes. Assume that the population standard deviations of the completion times can be estimated to be the sample standard deviations, since the samples that are used to compute them are quite large. At the 0.05 level of significance, is there enough evidence to support the claim that the mean completion time, μ1 , of Fundash is not equal to the mean completion time, μ2 , of Coolsprint?…arrow_forwardIn 2022, Los Angles Times reported that the mean fare to fly from San Francisco to Los Angeles, on a discount ticket was around $360. A random sample of round-trip discount fares on this route last month is provided below: At the 0.05 significance level, can we conclude that the mean fare has increased? Amount 390 386 390 430 410 350 370 380 399 365 391 375 381 400 389 410 398 358 421 398arrow_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





