Constructing a Confidence Interval when the Population σσ is Known Suppose scores on exams in statistics are normally distributed with an unknown population mean and a population standard deviation of 3 points. A random sample of 36 scores is taken and gives a sample mean of 68. Find a 95% confidence interval estimate for the population mean exam score by providing the following information.
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Constructing a Confidence Interval when the Population σσ is Known
Suppose scores on exams in statistics are
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- Daily Driving The average number of miles a person drives per day is 24. A researcher wishes to see if people over age 60 drive less than 24 miles per day. She selects a random sample of 25 drivers over the age of 60 and finds that the mean number of miles driven is 23.4. The population standard deviation is 4.1 miles. At a = 0.01, is there sufficient evidence that those drivers over 60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the critical value method with tables. Part 1 of 5 State the hypotheses and identify the claim with the correct hypothesis. H: u = 24 not claim Η: μ 24 claim The hypothesis test is a one-tailed test. Part: 1/5 Part 2 of 5 Find the critical value(s). Round the answer to at least two decimal places. If there is more than one critical value, separate them with commas. Critical value(s):Daily Driving The average number of miles a person drives per day is 24. A researcher wishes to see if people over age 60 drive less than 24 miles per day. She selects a random sample of 25 drivers over the age of 60 and finds that the mean number of miles driven is 22.5. The population standard deviation is 4.1 miles. At a = 0.01, is there sufficient evidence that those drivers over 60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the P-value method with a graphing calculator. Part: 0 / 4 Part 1 of 4 (a) State the hypotheses and identify the claim. H,: (Choose one) ▼ ODaily Driving The average number of miles a person drives per day is 24. A researcher wishes to see if people over age 60 drive less than 24 miles per day. She selects a random sample of 32 drivers over the age of 60 and finds that the mean number of miles driven is 22.9. The population standard deviation is 3.1 miles. At α=0.05, is there sufficient evidence that those drivers over 60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the P-value method with a graphing calculator. Find the P-value. Round it to four decimal places.The distribution of heights in a population of women is approximately normal. Sixteen percent of the women have heights less than 62 inches. About 97.5% of the women have heights less than 71 inches. Use the empirical rule to estimate the mean and standard deviation of the heights in this population. Mean: K inches Standard Deviation: inchesData on the weights (Ib) of the contents of cans of diet soda versus the contents of cans of the regular version of the soda is summarized to the right. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a 0.01 significance level for both parts. Diet Regular H2 27 27 0.79037 lb 0.80399 lb 0.00449 lb 0.00756 lb a. Test the claim that the contents of cans of diet soda have weights with a mean that is less than the mean for the regular soda. What are the null and alternative hypotheses? O A. Ho: H1 = H2 OB. Ho: H1#H2 Hq: HyBabies: A sample of 25 one-year-old girls had a mean weight of 24.1 pounds with a standard deviation of 4.3 pounds. Assume that the population of weights is normally distributed. A pediatrician claims that the standard deviation of the weights of one-year-old girls is greater than 7 pounds. Do the data provide convincing evidence that the pediatrician's claim is true? Use the =α0.05 level of significance.Part Variability is critical in the manufacturing of the ball bearings. Large variances in the size of the ball bearings cause bearing failure and rapid wear out. Production standards call for a maximum variance of .0001 when the bearing sizes are measured in inches. A sample of 15 bearings shows a sample standard deviation of .014. a. Compute the 90% confidence interval estimate of the variance of the ball bearings in the population. b. Use a= 0.10 to determine whether the sample indicates that the maximum acceptable variance is being exceeded. Use critical value approach. ( Note: You must state null and alternative hypotheses, compute the test statistic, Report the critical Value, and draw a conclusion.5/Do men talk less than women? The table shows results from a study of the words spoken in a day by men and women. Assume that the two samples are randomly selected, independent, the population standard deviations are not know and not considered equal. At the 0.05 significance level, test the claim that the mean number of words spoken by men is less than the mean number of words spoken by women. Men Women n1 = 212 n2 = 218 xˉx̄1 = 15706.4 words xˉx̄2 = 15683.2 words s1 = 1595.44 words s2 = 1597.54 words What are the correct hypotheses? (Select the correct symbols and use decimal values not percentages.)H0: Select an answer μ₁ μ σ₁² x̄₂ p x̄₁ s₁² p̂₁ μ(men) p₂ p₁ μ₂ ? ≤ > ≥ = ≠ < Select an answer μ₁ p₁ μ₂ x̄₂ σ₁² p̂₁ μ s₁² μ(women) p x̄₁ p₂ H1: Select an answer p̂₂ p s₂² σ₂² μ(men) μ μ₂ x̄₂ x̄₁ p₂ μ₁ p₁ ? < > = ≠ ≥ ≤ Select an answer μ₂ μ p₂ s₁² p₁ x̄₁ σ₁² p̂₁ p μ₁ x̄₂ μ(women) Original Claim = Select an answer H₁ H₀ df = Based on the hypotheses, find the…Daily Driving The average number of miles a person drives per day is 24. A researcher wishes to see if people over age 60 drive less than 24 miles per day. She selects a random sample of 25 drivers over the age of 60 and finds that the mean number of miles driven is 23.4. The population standard deviation is 4.1 miles. At a = 0.01, is there sufficient evidence that those drivers over 60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the critical value method with tables. Part: 0 / 5 Part 1 of 5 State the hypotheses and identify the claim with the correct hypothesis. Ho: (Choose one) OeBook The U.S. Energy Information Administration (US EIA) reported that the average price for a gallon of regular gasoline is $3.87. The US EIA updates its estimates of average gas prices on a weekly basis. Assume the standard deviation is $.24 for the price of a gallon of regular gasoline and recommend the appropriate sample size for the US EIA to use if they wish to report each of the following margins of error at 95% confidence. Round up to the next whole number. a. The desired margin of error is $.09. The appropriate sample size is b. The desired margin of error is $.06. The appropriate sample size is c. The desired margin of error is $.05. The appropriate sample size isIQ scores are normally distributed with a mean of 100 and a standard deviation of 15. A charter school wants to know if their students have an average IQ that is higher than the population average. They take a random sample of 25 students and find a mean IQ of 108 with a standard deviation of 21. Use a 5% significance level. What is the P value with work? Do we reject the null hypothesis in this case? What does the hypothesis test say about the mean pulse rate.SEE MORE QUESTIONSRecommended textbooks for youMATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th…StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C…StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. 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