Gary has discovered a new painting tool to help him in his work. If he can prove to himself that the painting tool reduces the amount of time it takes to paint a room, he has decided to invest in a tool for each of his helpers as well. From records of recent painting jobs that he completed before he got the new tool, Gary collected data for a random sample of 7 medium-sized rooms. He determined that the mean amount of time that it took him to paint each room was 3.6 hours with a standard deviation of 0.2 hours. For a random sample of 6 medium-sized rooms that he painted using the new tool, he found that it took him a mean of 3.2 hours to paint each room with a standard deviation of 0.3 hours. At the 0.05 level, can Gary conclude that his meantime for painting a medium-sized room without using the tool was greater than his meantime when using the tool? Assume that both populations are approximately normal and that the population variances are equal. Let painting times without using the tool be Population 1 and let painting times when using the tool be Population 2.
Trending nowThis is a popular solution!
Step by stepSolved in 2 steps with 2 images
- Suppose that, at the end of last semester, Marie gave her introductory statistics class a final exam. After grading these exams, she created a histogram illustrating the distribution of exam scores for the 70 students in the class. Each of the bars in this histogram includes only the left endpoint of the interval, except for the bar representing scores between 90 and 100 points, which also includes the right endpoint. What percentage of students scored between 60 and 80 points on the exam? Round your answer to the nearest tenth of a percent. Number of students who scored at least 80 points = students Percentage of students who scored between 60 and 80 points = %arrow_forwardA group of migraine headache sufferers were tracked over their lifetimes with data taken every 10 years. The scatter plot shows the number of headaches per year versus age, in years. How would you estimate the number of headaches at age 100? Question 2 options: Draw a line of best fit and interpolate. Wait until a sufficient number of subjects have reached the age of 100. Draw a line of best fit and extrapolate. Use the number from age 80 and divide by 2.arrow_forwardYou are a big soccer fan and you decide to gather information on the goal differential (goals scored - goals allowed) for your favorite team in the Premier League during the last season. You find that the average goal differential for home games (games that take place on the team's own stadium) was 1.37 and the average goal differential for away games (games that take place on the opponent team's stadium) was 0.32. With the data you have, if you regress goal differential (call it variable G) on a dummy variable (call it variable D) that takes the value 1 if the game is a home game and takes the value zero if the game is an away game, and obtain Ĝi = Bo + B₁ D₁, then, Bo will be equal to equal to and ₁ will bearrow_forward
- Mr. Palmer, has been teaching beginners how to fix their stroke for the last 10 years. The mean golfing score for all past students who learned with Mr. Palmer is 79. This golfing cycle, he tried a new teaching method using simulations instead of real-world golf. He then had 15 of his students that used his new method take a golfing test. Enter the data into SPSS. Use this dataset to answer this question: did Mr. Palmer’s students perform better on the golfing test using the new method as compared to the traditional teaching technique? 1. From the output, report the test statistic and the probability (obtained p-value, called “sig” in the output). Remember to include degrees of freedom when you report t-values. 2. Will you reject or fail to reject the null based on the SPSS output (Remember to use numbers from the output only to make your statistical conclusion. If you use a critical t, you will get no points.).arrow_forwardThe results obtained above were primarily due to the mean for the third treatment being noticeably different from the other two sample means. For the following data, the scores are the same as above except that the difference between treatments was reduced by moving the third treatment closer to the other two samples. In particular, 3 points have been subtracted from each score in the third sample. Before you begin the calculation, predict how the changes in the data should influence the outcome of the analysis. That is, how will the F-ratio for these data compare with the F-ratio from above? Treatment A Treatment B Treatment C 1 4 3 2 1 1 3 2 7 2 3 4 F-ratio = p-value = Conclusion: O These data do not provide evidence of a difference between the treatments O There is a significant difference between treatmentsarrow_forwardThe results obtained above were primarily due to the mean for the third treatment being noticeably different from the other two sample means. For the following data, the scores are the same as above except that the difference between treatments was reduced by moving the third treatment closer to the other two samples. In particular, 3 points have been subtracted from each score in the third sample. Before you begin the calculation, predict how the changes in the data should influence the outcome of the analysis. That is, how will the F-ratio for these data compare with the F-ratio from above? Treatment A Treatment B Treatment C 4 6. 7 3 9. 3. 4 3. F-ratio = p-value = Conclusion: O These data do not provide evidence of a difference between the treatments There is a significant difference between treatments Submit Question M hparrow_forward
- On average, a sample of n = 36 scores will provide a better estimate of the population mean than a sample of n = 49 scores from the same population.arrow_forwardIn a data set with 25 scores, if the value 16 occurs 12 times, what is its relative frequency?arrow_forwardClara and Rose work at different companies. Clara earns an annual salary of 55,500 and Rose earns an annual salary of 58,000, but they are curious to know whose salary is closer to the mean salary at her company. Clara calculates a z-score of z=−0.45 for her salary, when compared to her company, and Rose calculates a z-score of z=−0.33. Whose salary is closer to the mean salary at her company? Select the correct answer below:arrow_forward
- It seems that of engaged women buy a wedding dress at least one size smaller than their current size. Why? Cornell researchers reported an alarming tendency for women who are engaged to sometimes attempt to lose an unhealthy amount of weight prior to their wedding (Neighbors & Sobal, 2008). The researchers found that engaged women weighed, on average, 152.1 pounds. The average ideal wedding weight reported by 227 women was 136.0 pounds. The data below represent the fictional weights of eight women on the day they bought their wedding dress and on the day they got married. Did women lose weight for their wedding day? Dress purchase Wedding day 163 158 144 139 151 150 120 118 136 132 158 152 155 150 145 146 Conduct the six steps of hypothesis testing using a one-tailed test and an alpha level of 0.05. Report the test statistic in APA format. Calculate the confidence interval for the paired-samples t test that you conducted in part (a). Compare the…arrow_forwardThe results obtained above were primarily due to the mean for the third treatment being noticeably different from the other two sample means. For the following data, the scores are the same as above except that the difference between treatments was reduced by moving the third treatment closer to the other two samples. In particular, 3 points have been subtracted from each score in the third sample. Before you begin the calculation, predict how the changes in the data should influence the outcome of the analysis. That is, how will the F-ratio for these data compare with the F- ratio from above? Treatment A F-ratio= = p-value = 6 5 4 LO 5 5 Treatment B Treatment C 5 6 8 4 6 8 7 7 4 10arrow_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