In Exercises 5–20, assume that the two samples are independent simple random samples selected from
18. Car and Taxi Ages When the author visited Dublin. Ireland (home of Guinness Brewery employee William Gosset, who first developed the t distribution), he recorded the ages of randomly selected passenger cars and randomly selected taxis. The ages can be found from the license plates. (There is no end to the fun of traveling with the author.) The ages (in years) are listed below. We might expect that taxis would be newer, so test the claim that the
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- The body mass index (BMI) of a person is the person’s weight divided by the square of his or her height. It is an indirect measure of the person’s body fat and an indicator of obesity. Results from surveys conducted by the Centers for Disease Control and Prevention (CDC) showed that the estimated mean BMI for US adults increased from 25.0 in the 1960–1962 period to 28.1 in the 1999–2002 period. [Source: Ogden, C., et al. (2004). Mean body weight, height, and body mass index, United States 1960–2002. Suppose you are a health researcher. You conduct a hypothesis test to determine whether the mean BMI of US adults in the current year is greater than the mean BMI of US adults in 2000. Assume that the mean BMI of US adults in 2000 was 28.1 (the population mean). You obtain a sample of BMI measurements of 1,034 US adults, which yields a sample mean of M = 28.9. Let μ denote the mean BMI of US adults in the current year. Please Formulate the null and alternative hypothesesarrow_forwardType I and Type I l Errors. In Exercises 29–32, provide statements that identify the type I error and the type II error that correspond to the given claim. (Although conclusions are usually expressed in verbal form, the answers here can be expressed with statements that include symbolic expressions such as p = 0.1.) The proportion of people with blue eyes is equal to 0.35.arrow_forwardType I and Type I l Errors. In Exercises 29–32, provide statements that identify the type I error and the type II error that correspond to the given claim. (Although conclusions are usually expressed in verbal form, the answers here can be expressed with statements that include symbolic expressions such as p = 0.1. The proportion of people who require no vision correction is less than 0.25.arrow_forward
- Scientists conducting a study on global climate change want to determine if there has been an increase in the number of days per year that the temperature in El Paso rises above 100 degrees Fahrenheit. In 1981, there were 21 days where the temperature rose above 100 degrees Fahrenheit. The scientists want to know whether the average number of days per year that the temperature rises above 100 degrees Fahrenheit has increased. Which hypothesis test would be most appropriate for this study? O One mean (sigma known) - one sample z O One mean (sigma unknown) - one sample t O Mean of differences, using dependent samples (paired data) O Difference of two means (independent samples) O Several means (ANOVA) O One proportion O Difference of two proportions O Chi-Squared test for independencearrow_forwardIn Exercises 5–12, identify whether the given value is a statistic or a parameter. Birth Weight In a study of 400 babies born at four different hospitals in New York State, it was found that the average (mean) weight at birth was 3152.0 grams.arrow_forwardIdentifying H0 and H1 In Exercises 5–8, do the following: a. Express the original claim in symbolic form. b. Identify the null and alternative hypotheses. Pulse Rates Claim: The standard deviation of pulse rates of adult males is more than 11 bpm. For the random sample of 153 adult males in Data Set 1 “Body Data” in Appendix B, the pulse rates have a standard deviation of 11.3 bpm.arrow_forward
- Solve with clear solutionarrow_forwardSuppose that 95% of the bags of certain fertilizer mix weigh between 49 and 53 pounds. Averages of three succesive bags were plotted, and 47.5% of these were observed to lie between 51 and X pounds. Estimate the value of X. State assumptions you make and say whether these assumptions are likely to be true for this example.arrow_forwardPart C and Darrow_forward
- A purchasing agent obtained 60 watt bulbs from two companies. He has the samples tested in his laboratory for the length of the life with the following results: Length of Life (in hours) 1700 and under 1900 1900 and under 2100 2100 and under 2300 2300 and under 2500 2500 and under 2700 Соmpany A Соmpany B 12 3 14 30 20 17 8 6 2 a. Which Company's bulb do you think are better in terms of average life? b. If price of both types are the same, which company's bulbs would you buy and why? ( Coefficient of variation is Mean /Standard deviation **100)arrow_forwardHealth care workers who use latex gloves with glove powder on a daily basis are particularly susceptible to developing a latex allergy. Each in a sample of 44 hospital employees who were diagnosed with a latex allergy based on a skin-prick test reported on their exposure to latex gloves. Summary statistics for the number of latex gloves used per week are x= 19.4 and s = 11.7. Complete parts (a) - (d). a. Give a point estimate for the average number of latex gloves used per week by all health care workers with a latex allergy. b. Form a 95% confidence interval for the average number of latex gloves used per week by all health care workers with a latex allergy. (Use integers or decimals for any numbers in the expression. Round to two decimal places as needed.) c. Give a practical interpretation of the interval, part (b). O A. One can be 95% confident that latex gloves cause allergies for all who use a number of gloves contained in the interval. O B. One can be 95% confident that the…arrow_forwardIn Exercises 13–20, use the data in the table below for sitting adult males and females (based on anthropometric survey data from Gordon, Churchill, et al.). These data are used often in the design of different seats, including aircraft seats, train seats, theater seats, and classroom seats. (Hint: Draw a graph in each case.) Sitting Back-to-Knee Length (inches) Find the probability that a female has a back-to-knee length greater than 24.0 in.arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill