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 6 medium-sized rooms. He determined that the mean amount of time that it took him to paint each room was 3.8 hours with a standard deviation of 0.2 hours. For a random sample of 8 medium-sized rooms that he painted using the new tool, he found that it took him a mean of 3.4 hours to paint each room with a standard deviation of 0.3 hours. At the 0.05 level, can Gary conclude that his mean time for painting a medium-sized room without using the tool was greater than his mean time 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. Step 3 of 3: Draw a conclusion and interpret the decision. 田 Tables E Keypad Answer Keyboard Shortcuts We reject the null hypothesis and conclude that there is insufficient evidence at a 0.05 level of significance to support Gary's claim that his mean time for painting a medium-sized room without using the tool is greater than his mean time when using the tool. We fail to reject the null hypothesis and conclude that there is sufficient evidence at a 0.05 level of significance to support Gary's claim that his mean time for painting a medium-sized room without using the tool is greater than his mean time when using the tool. We fail to reject the null hypothesis and conclude that there is insufficient evidence at a 0.05 level of significance to support Gary's claim that his mean time for painting a medium-sized room without using the tool is greater than his mean time when using the tool. We reject the null hypothesis and conclude that there is sufficient evidence at a 0.05 level of significance to support Gary's claim that his mean time for painting a medium-sized room without using the tool is greater than his mean time when using the tool.

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.).

A study was undertaken to see how accurate food labeling for calories on food that is considered reduced calorie. The group measured the amount of calories for each item of food and then found the percent difference between the measured and labeled amount of calories. The group also looked at food that was nationally advertised, regionally distributed, or locally prepared. Do the data indicate that at least one of the mean percent differences between the three groups is different from the others? The data is summarized in the table below. National Mean Standard Deviation Sample Size Local -2.1 Regional 27.1667 143.125 Fill in the hypotheses below: Ho: Select an answer Ha: Select an answer 10.3257 20.797 53.5922 20 12 8

Surveys always provide data that is 100% accurate from feedback from participants True or False

A high school teacher would like to examine his students’ exam scores based on seating arrangements. He assigned n = 15 students to sit in the last three rows of his class and n = 15 students to sit in the first three rows. Each student received a 45-minute lecture for one week and were given the same exam the following school day. The front row students had a mean of M = 78 with SS = 10.50 on their exam. And the back row students had a mean of M = 72 with SS = 8.90. Is there a significant difference in exam scores? Test with  = .05.

A researcher has found a strong relationship between level of education and income and concludes that “higher levels of education cause higher income.” What error has been made?

If a students rank in a class of 200 is 12, find the students percentile rank

An Internet retailer would like to investigate the relationship between the amount of time in minutes a purchaser spends on its Web site and the amount of money he or she spends on an order. The table to the right shows the data from a random sample of

Here is an example from John and Jenn. When we return exams in our classes, we find it beneficial to share with students information on the distribution of scores. We provide this information so that students will have an idea of how they scored on the exam in comparison to their peers. However, deciding which descriptive information to provide to the class is not always an easy decision. These are modified grades from one of Jenn’s statistics classes. For this data set, the mean is 77, the mode is 92, and the median is 86. If you were the professor of the class, do you think sharing the mean scores on the exam with the class is a representative score of the data set? Why or why not? 9 or 11. The researchers predicted that the more a mother weighed during pregnancy, the higher the fat mass would be in the child. Such findings would support the developmental over nutrition hypothesis, which states that overeating during key developmental times has an influence on the offspring. The…

Please also explain why you determined whether or not the results are statistically significant.  In another memory experiment, the mean scores for participants in Condition A and Condition B came out exactly the same!