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1. A researcher wishes to estimate the average blood alcohol concentration for drivers involved in fatal accidents who are found to have positive BAC(blood alcohol concentration) values. He randomly selects records from 1100 such drivers in 2009 and determines the sample mean BAC to be 0.15 g/dL. with a standard deviation of 0.07 g/dL.Determine and interpret a 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC.The 90% confidence interval for the mean BAC is (0.147, 0.153). Round to the nearest thousandth.We are 90% confident that the mean BAC in fatal crashes in which the driver had a positive BAC is in the interval (0.147, 0.153).2. a poll was conducted that asked 1006 people how many books they had read in the past year. Results indicated that x bar=10.4 books and (standard deviation=16.6 books). Construct a 90% confidence interval for the Mean number of books people read.Round to 2 decimal places. (9.54 , 11.26)Use ascending order in your answer.3. the following data represents the concentration of organic carbon (mg/L) collected from organic soil. Construct a 99% confidence interval for the mean concentration of dissolved organic carbon collected from organic soil. (Note: x bar=18.04 mg/L and standard deviation=7.76 mg/L) (n=20) (13.08, 23.00) (use ascending order. Round to 2 decimal places as needed.)4. a doctor wants to estimate the HDL cholesterol of all 20-29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99% confidence assuming standard deviation=18.3 based on earlier studies? Suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required?a. A 99% confidence level requires how many subjects? 556(round to the nearest subject.)b. A 95% confidence level requires how many subjects? 322(round to the nearest subject.)If the confidence decreases then sample size decreases?5. people were polled on how many books they read the previous year. Initial survey results indicate that s=16.2 books. Complete parts a through d below.a. How many subjects are needed to estimate the numberof books read the previous year within 6 books with 90% confidence Answer: 20b. How many subjects are needed to estimate the number of books read the previous year within 3 books with 90% confidence?Answer: 79?c. what effect does doubling the required accuracyA. doubling the required accuracy quadruples the sample size.B. doubling the required accuracy halves the sample sizeC. doubling the required accuracy quarters the sample sizeD. doubling the required accuracy doubles the sample size.?d. How many subjects are needed to estimate the number of books read the previous year within 6 books with 99% confidence?Answer: 49?6. a null and alternative hypothesis are given. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. What parameter is being tested?H subscript 0: sigma = 9H subscript 1: sigma < 9a. what type of test is being conducted in this problem?A. left-tailed testB. right-tailed test C. two-tailed testb. what parameter is being tested?A. population meanB. population proportionC. population standard deviation7. a null and alternative hypothesis are given. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. What parameter is being tested?H subscript 0: sigma= 4.2H subscript 1: sigma does not equal 4.2a. choose the correct answer below.A. two- tailedB. left-tailedC. Right-tailedb. what parameter is being tested?A. pB. sigmaC. Mu8. a null and alternative hypothesis are given. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. What parameter is being tested? H subscript 0: sigma =120 H subscript 1: sigma >120a. Is the hypothesis test left-tailed, right-tailed, or two-tailed? Right-tailedb. what parameter is being tested?A. population standard deviationB. population meanC. population proportion9. The mean consumption of fruit three years ago was 98.2 pounds. A dietician believes that fruit consumption has risen since then.a. determine the null and alternative hypothesis. Which of the following is correct?A. H subscript 0: Mu=98.2; H subscript 1: Mu > 98.2B. H subscript 0: Mu=98.2; H subscript 1: Mu < 98.2C. H subscript 0: Mu=98.2; H subscript 1: Mu ≠ 98.210. In a clinical trial, 16 out of 750 patients taking a prescription drug complained of flulike symptoms. Suppose that its known that 1.5% of patients taking competing drugs complain of flulike symptoms. Is there sufficient evidence to conclude that more than 1.5% of this drug’s users experience flulike symptoms as a side effect at the α= 0.01 level of significance???a. What are the null and alternative hypothesis?(H subscript 0: p =, >,<, or ≠ how much) versus p = 0.015 (H subscript 1: p =,>, <, or ≠ how much) p > 0.015b. use a calculator to find the P-value. Round to 3 decimal places 0.07711. In a previous poll, 27% of adults with children under the age 18 reported that their family ate dinner together 7 nights a week. Suppose that, in a more recent poll, 321 of 1300 adults with children under the age of 18 reported that their family ate dinner together 7 nights a week. Is there sufficient evidence that their proportion of families with children under the age 18 who eat dinner together 7 nights a week has decreased at the α=0.01 significance level?a. what are the null and alternative hypotheses?(H subscript 0: p =, >, <, or ≠ how much) versus p = 0.27(H subscript 1: p =, <, >, or ≠ how much) p < 0.2712. several years ago, 42% of parents who had children in grades K-12 were satisfied with the quality of education the students receive. A recent poll asked 1,155 parents who have children in grades K-12 if they were satisfied with the quality of education the students receive. Of the 1,155 surveyed, 493 indicated that they were satisfied. Construct a 90% confidence interval to assess whether this represents evidence that parents’ attitude toward the quality of education have changed.a. what are the null and alternative hypotheses?H0: p = 0.42Ha: p 0.42b. use a calculator to find the 95% confidence interval (0.398, 0.455) 13. In a survey, 38% of the respondents stated that they talk to their pets on the answering machine or telephone. A veterinarian believed that this result to be too high, so she randomly selected 150 pet owners and discovered that 51 of them spoke to their pet on the answering machine or telephone. Does the veterinarian have a right to be skeptical? Use the α=0.1 level of significance.?a. what are the null and alternative hypotheses?(H subscript 0: p =, >, <, or ≠ how much) versus p=0.38(Hsubscript 1: p =, >, <, or ≠ how much) p<0.38b. use a calculator to find the P- value. (round to 3 decimal places) 0.15614. previously, 3% of mothers smoked more than 21 cigarettes during their pregnancy. An obstetrician believes that the percentage who smoke 21 cigarettes or more is less than 3% today. She randomly selects 115 pregnant mothers and finds that 2 of them smoked 21 or more cigarettes during pregnancy. Test the researcher’s statement at the α= 0.05 level of significance.a. identify the correct null and alternative hypotheses.(H subscript 0: p =, >, <, or ≠ 0.03) versus p = 0.03(H subscript 1: p =, >, <, or ≠ 0.03) p < 0.03b. use a calculator to find the P-value. ( round to 3 decimal places). 0.21415. for every football game there is a team that’s expected to win by a certain number of points. In betting parlance, this is called the spread. If point spreads are accurate, we would expect about half of all games played to result in the favored team winning (beating the spread) and about half of all games to result in the team favored to not beat the spread. The accompanying data represent the results of 45 randomly selected games where a 0 indicates the favored team did not beat the spread and a 1 indicates the favored team beat the spread. Do the data suggest that sport books establish accurate spreads?a. identify the correct null and alternative hypotheses.(H subscript 0: p =, >, <, or ≠ 0.5) versus p = 0.5(H subscript 1:p =, >, <, or ≠ 0.5) p 0.5b. use a calculator to find the P- value. (round to 3 decimal places.) 0.65516. to test (H subscript 0: Mu=100) versus (H subscript 1: Mu≠100), a simple random sample size of n=15 is obtained from a population that is known to be normally distributed. a. if x bar=104 and s=8.1, complete the test statistic.t= how much.( round to 3 decimal places.) 1.913b. if the researcher decides to test this hypotheses at the α=0.01 level of significance, determine the 2 critical values. -2.977, 2.977c. draw a t-distribution that depicts the critical region(s)17. Several years ago, the mean height of women 20 years of age or older was 63.7 inches. Suppose that a random sample of 45 women who are 20 years of age or older today results in a mean height of 64.7 inches.a. state the appropriate null and alternative hypotheses toassess whether women are taller today.A. (H subscript 0: Mu=63.7 inches) vs. (H subscript 1: Mu >63.7 inches)B. (H subscript 0: Mu=64.3 in.) vs. (H subscript 1: Mu< 64.3 in.)C. (H subscript 0: Mu=64.3 in.) vs. (H subscript 1: Mu≠64.3 in.)D. (H subscript 0: Mu=63.7 in.) vs. (H subscript 1: Mu <63.7 in.)E. (H subscript 0: Mu=64.3 in.) vs. (H subscript 1: Mu >64.3 in.)F. (H subscript 0: Mu=63.7 in.) vs. (H subscript 1: Mu≠63.7 in.)?b. suppose the P-value for this test is 0.19. explain what this value represents.A. there’s a 0.15 probability of obtaining a sample mean weight of 64.8 inches or shorter from a population whose mean height is 63.7.B. there’s a 0.15 probability of obtaining a sample mean weight of exactly 64.8 inches from a population whose mean height is 63.7.C. there’s a 0.15 probability of obtaining a sample mean weight of 64.8 inches or tallerfrom a population whose mean height is 63.7.?18. researchers wanted to measure the effect of alcohol on the development of the hippocampal region in adolescents. The researchers randomly selected 11 adolescents with alcohol use disorders. They wanted to determine whether the hippocampal volumes in the alcoholic adolescents were less than the normal volume of 9.02 cm cubed. An analysis of the sample data revealed that the hippocampal volume is approximately normal with x bar=8.38 and s=0.7. conduct an appropriate test at the α=0.05 level of significance.?a. choose the correct hypotheses.(H subscript 0: (Mu, p, or sigma)(=, <, >, or ≠) 9.02) u=9.02(H subscript 1: (Mu, p, or sigma)(=, <, >, or ≠) 9.02) u<9.02b. t subscript 0= how much? (round to 2 decimal places as needed) -3.03 c. find the P-value. (round to 3 decimal places as needed.) 0.00619. A health administration recommends that individuals consume 950 mg of calcium daily. After an advertising campaign aimed at male teenagers, a dairy association states that male teenagers consume more than the recommended daily amount of calcium. To support this statement, the association obtained a random sample of 40 male teenagers and found that the mean amount of calcium consumed was 955 mg, with a standard deviation of 120 mg. is there significant evidence to support the statement of the association at the α=0.05 level of significance.a. (H subscript 0: (Mu, p, or sigma)(=, <, >, or ≠) 950) ? = 950(H subscript 1: (Mu, p, or sigma)(=, <, >, or ≠) 950) ? > 950b. Find the test statistic.T subscript 0= how much 0.26(round to 2 decimal places as needed.)c. Find the P-value. 0.39720. Several years ago, the reported mean age of an inmate on death row was 44.4 years. A sociologist wondered whether the mean age of a death-row inmate has changed since then. He randomly selects 34 death-row inmates and finds that their mean age is 46.2, with a standard deviation of 9.4. Construct a 90% confidence interval about the mean age of death row inmates.a. choose the correct hypotheses.(H subscript 0: (Mu, p, or sigma)(=, <, >, or ≠) 44.4) ?=44.4(H subscript 1: (Mu, p, or sigma)(=, <, >, or ≠) 44.4) ?44.4b. construct a 90% confidence interval about the mean age.(use ascending order. Round to 2 decimal places as needed.) CI = (43.55,48.85)?21. A golf association requires that golf balls have a diameter that is 1.68 inches. To determine if golf balls conform to the standards, a random sample of golf balls was selected. Their diameters are shown in the table.a. Do the golf balls conform to the standards? Conduct a hypothesis test using the P-value approach and a level of significance of α=0.05 level of significance.First determine the appropriate hypotheses.(H subscript 0: (Mu, p, or sigma)(=, <, >, or ≠)1.68) ?=1.68(H subscript 1: (Mu, p, or sigma)(=, <, >, or ≠)1.68) ?1.68Find the test statistic.t subscript 0= how much (round to 2 decimal places as needed.) 0.91Find the P-value. (round to 3 decimal places as needed.) 0.382?22. The average daily volume of a computer stock in 2000 was Mu=35.1 million shares, according to a reliable source. A stock analyst believes that the stock volume in 2004 is different from the 2000 level. Based on a random sample of 30 trading days in 2004, he finds the sample mean to be 25.4 million shares, with a standard deviation of s=11.6 million shares. Test the hypotheses by constructing a 95% confidence interval. a. state the hypotheses for the test.(H subscript 0: (Mu, p, or sigma)(=, <, >, or ≠)35.1) ??= 35.1(H subscript 1: (Mu, p, or sigma)(=, <, >, or ≠)35.1) ?? 35.1b. construct a 95% confidence interval about the sample mean of stocks traded in 2004.(21.249, 29.551) (use ascending order. Round to 3 decimal places as needed.)Let me know if you have any doubt , and let me know the scoreGOOD LUCK ! ................
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