Testing Hypotheses. In Exercises 9-24, assume that a simple random sample has been selected and test the given claim. Unless specified by your instructor, use either the P-value method or the critical value method for testing hypotheses. Identify the null and alternative hypotheses, test statistic, P-value (or
16. Flight Delays Data Set 15 in Appendix B lists 48 different departure delay times (minutes) for American .Airlines flights from New York (JFK) to Los Angeles. Negative departure delay times correspond to flights that departed early. The
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- We are interested in whether the proportions of female suicide victims for ages 15 to 24 are the same between the white and the black races in the United States. We randomly pick one year to compare the races. The number of suicides estimated in the United States in that year for white females is 4,930. Five hundred eighty-three were aged 15 to 24. The estimate for black females is 330. Forty-one were aged 15 to 24. We will let female suicide victims be our population. (Use α = 0.05.) NOTE: If you are using a Student's t-distribution for the problem, including for paired data, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) Part (a) State the null hypothesis. ○ Ho: PW> PB O Ho: PW + PB Ho: Pw≤ PB Ho: PW-PB ○ Ho: Pw PB Part (c) In words, state what your random variable P'w-P'B represents. P'w-P'B represents the average difference of white and black female suicide victims, aged 15 to 24. ○ P'w-P'B…arrow_forwardplease solve this problem step by step and make it quick pleasearrow_forwardplease solve this problem step by step and make it quick pleasearrow_forward
- 8.67 Free recall memory strategy. Psychologists who study ①memory often use a measure of "free recall" (e.g., the RECALL number of correctly recalled items in a list of to-be- remembered items). The strategy used to memorize the list-for example, category clustering-is often just as important. Researchers at Central Michigan University developed an algorithm for computing measures of cat- egory clustering in Advances in Cognitive Psychology (Oct. 2012). One measure, called ratio of repetition, was recorded for a sample of 8 participants in a memory study. These ratios are listed in the table. Test the theory that the average ratio of repetition for all participants in a similar memory study differs from .5. Select an appropriate Type I error rate for your test. .25 .43 .57 .38 .38 .60 .47 .30 Source: Senkova, O., & Otani, H. "Category clustering calculator for free recall." Advances in Cognitive Psychology, Vol. 8, No. 4, Oct. 2012 (Table 3).arrow_forward8.64 Radon exposure in Egyptian tombs. Refer to the D Radiation Protection Dosimetry (Dec. 2010) study TOMBS of radon exposure in Egyptian tombs, Exercise 7.39 (p. 334). The radon levels-measured in becquerels per cubic meter (Bq/m³)-in the inner chambers of a sam- ple of 12 tombs are listed in the table. For the safety of the guards and visitors, the Egypt Tourism Authority (ETA) will temporarily close the tombs if the true mean level of radon exposure in the tombs rises to 6,000 Bq/m³. Consequently, the ETA wants to conduct a test to deter- mine if the true mean level of radon exposure in the tombs is less than 6,000 Bq/m³, using a Type I error probabil- ity of .10. A SAS analysis of the data is shown on p. 399. Specify all the elements of the test: Ho, Ha, test statistic, p-value, a, and your conclusion. 50 390 910 12100 180 580 7800 4000 3400 1300 11900 1100 N Mean Std Dev Std Err Minimum Maximum 12 3642.5 4486.9 1295.3 50.0000 12100.0arrow_forwardHow does probability help businesses make informed decisions under uncertainty? Provide an example of how businesses use probability in marketing to predict customer behavior. Why is probability considered essential in financial decision-making, particularly in portfolio management? Discuss how the use of probability in inventory management can improve customer satisfaction. Compare the role of probability in marketing and financial decision-making. How do the applications differ in their objectives?arrow_forward
- 55 5.5 A glass bottle manufacturing company has recorded data on the average number of defects per 10,000 bottles due to stones (small pieces of rock embedded in the bottle wall) and the number of weeks since the last furnace overhaul. The data are shown below. Defects per 10,000 Weeks 13.0 4 16.1 5 14.5 6 17.8 7 22.0 8 27.4 9 16.8 10 65.6 ☐☐ Defects per 10,000 Weeks 34.2 11 12 49.2 13 66.2 81.2 87.4 14 15 16 114.5 17 a. Fit a straight-line regression model to the data and perform the standard tests for model adequacy. b. Suggest an appropriate transformation to eliminate the problems encoun- tered in part a. Fit the transformed model and check for adequacy.arrow_forwardOne estimate of the proportion of children with autism in the United States is 1 in 100 (Source: http://www.cbsnews.com/stories/2009/10/05/health/main5363192.shtml). Suppose you are interested in the rate of autism among current school-aged children in Utah. You collect a sample of 400 children between the ages of 5 and 18 and find that three have had a previous diagnosis of an autism disorder. You plan to calculate a 95% confidence interval estimator of the proportion of school-aged children in Utah who have ever had a diagnosis of an autism disorder. Which of the following is the most likely reason you would use a Wilson estimator to calculate the confidence interval estimator? It is uncomfortable to define having been diagnosed with autism as a success. It is possible that if even the actual proportion in Utah is 1%, your sample may only have very few children who have had a previous diagnosis of an autism disorder. It is an easier way to calculate the confidence…arrow_forwardProblem 2-6. Need help on why its 1.22arrow_forward
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