"Advertising expenses are a significant component of the cost of goods sold. Listed below is a frequency distribution showing the advertising expenditures for 73 manufacturing companies located in the Southwest. The mean expense is $50.27 million and the standard deviation is $10.93 million. Is it reasonable to conclude the sample data are from a population that follows a normal probability distribution? Advertising Expense ($ Million) Number of Companies 25 up to 35 35 up to 45 45 up to 55 55 up to 65 65 up to 75 18 29 12 Total 73 Click here for the Excel Data File State the decision rule. Use the 0.10 significance level. (Round your answer to 2 decimal places.) Ho: The population of advertising expenses follows a normal distribution. H: The population of advertising expenses does not follow a normal distribution. Reject H0 if chi-square > Compute the value of chi-square. (Round your answer to 2 decimal places.) Chi-square value What is your decision regarding Hg? H0. This data from a normal distribution. could be The Damon family owns a large grape vineyard in western New York along Lake Erie. The grapevines must be sprayed at the beginning of the growing season to protect against various insects and diseases. Two new insecticides have just been marketed: Pernod 5 and Action. To test their effectiveness, three long rows were selected and sprayed with Pernod 5, and three others were sprayed with Action. When the grapes ripened, 440 of the vines treated with Pernod 5 were checked for infestation. Likewise, a sample of 360 vines sprayed with Action were checked. The results are: Number of Vines Checked (sample size) Insecticide Number of Infested Vines Pernod 5 440 30 Action 360 36 At the 0.02 significance level, can we conclude that there is a difference in the proportion of vines infested using Pernod 5 as opposed to Action? Hint. For the calculations, assume the Pernod 5 as the first sample. 1. State the decision rule. (Negative amounts should be indicated by a minus sign. Do not round the intermediate values. Round your answers to 2 decimal places.) H0 is rejected if z < or z> b. Compute the pooled proportion. (Do not round the intermediate values. Round your answer to 2 decimal places.) Pooled proportion c. Compute the value of the test statistic. (Negative amount should be indicated by a minus sign. Do not round the intermediate values. Round your answer to 2 decimal places.) Value of the test statistic

Some commercial airplanes recirculate approximately 50% of the cabin air in order to increase fuel efficiency. The researchers studied 1100 airline passengers, among which some traveled on airplanes that recirculated air and others traveled on planes that did not recirculate air. Of the 515 passengers who flew on planes that did not recirculate air, 108 reported post-flight respiratory symptoms, while 112 of the 585 passengers on planes that did recirculate air reported such symptoms. Is there sufficient evidence to conclude that the proportion of passengers with post-flight respiratory symptoms differs for planes that do and do not recirculate air? Test the appropriate hypotheses using ? = 0.05. You may assume that it is reasonable to regard these two samples as being independently selected and as representative of the two populations of interest. (Use a statistical computer package to calculate the P-value. Use pdo not recirculate − pdo recirculate. Round your test statistic to two…

Many states mandate tests that have to be passed in order for the students to graduate with a high school diploma. A local school superintendent believes that after-school tutoring will improve the scores of students in his district on the state's graduation test. As a trial run, a tutor agrees to work with 15 students for a month. The superintendent ask the school board to implement this after-school tutoring program if there is evidence that student scores would increase by an average of more than 20 points. Create a 95% confident level to estimate the true score increase. 25.4 23.3 17.8 21.3 14.8 28.8 22.5 23.6 32.3 15.4 23.4 27.5 18.8 19.1 20.4 a. Confidence Interval b. Conclusion

Many regions in North and South Carolina and Georgia have experienced rapid population growth over the last 10 years. It is expected that the growth will continue over the next 10 years. This has motivated many of the large grocery store chains to build new stores in the region. The Kelley’s Super Grocery Stores Inc. chain is no exception. The director of planning for Kelley’s Super Grocery Stores wants to study adding more stores in this region. He believes there are two main factors that indicate the amount families spend on groceries. The first is their income and the other is the number of people in the family. The director gathered the following sample information.  Family Food Income Size 1   $ 5.04   $ 73.98   4 2     4.08     54.90   2 3     5.76     94.14   4 4     3.48     52.02   1 5     4.20     65.70   2 6     4.80     53.64   4 7     4.32     79.74   3 8     5.04     68.58   4 9     6.12     165.60   5 10     3.24     64.80   1 11     4.80…

You are concerned that nausea may be a side effect of Tamiflu, but you cannot just give Tamiflu to patients with the flu and say that nausea is a side effect if people become nauseous. This is because nausea is common for people who have the flu. From past studies you know that about 30% of people who get the flu experience nausea. You collected data on 1744 patients who were taking Tamiflu to relieve symtoms of the flu, and found that 572 experienced nausea. Use a 0.01 significance level to test the claim that the percentage of people who take Tamiflu for the relief of flu symtoms and experience nausea is greater than 30%.a) Identify the null and alternative hypotheses?�0:               �1:               b) What type of hypothesis test should you conduct (left-, right-, or two-tailed)? left-tailed right-tailed two-tailed c) Identify the appropriate significance level.d) Calculate your test statistic. Write the result below, and be sure to round your final answer to two decimal…

A researcher wants to determine the specificity of mammograms to determine how effective they are at diagnosing women who have breast cancer. Assume the researcher obtained the results below from a study:  Out of a total of 18 women with breast cancer, 12 screened positive and 6 screened negative on the mammogram. Out of a total of 82 women without breast cancer, 5 screened positive and 77 screened negative on the mammogram. Calculate and interpret the specificity of mammograms for detecting breast cancer.