SOPHIA_INTRO TO STATISTICS_UNIT 5_CHALLENGE 3.pdf. QUESTIONS WITH ACCURATE ANSWERS.

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1.) The cholesterol level of children is normally distributed. If the average cholesterol level is 194 with a standard deviation of 15, what percentage of children have a cholesterol level lower tha... n 199? Answers are rounded to the nearest whole percent.  a.) 74%  b.) 63%  c.) 37%  d.) 26% 2.) Jason sampled 60 smokers who were questioned about the number of hours they sleep each day. Jason wants to test the hypothesis that the smokers need less sleep than the general public which needs an average of 7.5 hours of sleep with a population standard deviation of 0.7 hours. If the sample mean is 7.2 hours, what is the z-score? Answers are rounded to the hundredths place.  a.) 2.67  b.) -3.32  c.) -0.33  d.) 0.67 3.) An article claims that 12% of trees are infested by a bark beetle. A random sample of 1,000 trees were tested for traces of the infestation and found that 127 trees were affected. Using the formula and data provided, what is the value of the z-test statistic? Answer choices are rounded to the hundredths place.  a.) 0.50  b.) 0.70  c.) 0.25  d.) 0.35 4.) Select the correct statement.  a.) The critical z-score for a right-tailed test at a 17% significance level is 0.57.  b.) The critical z-score for a two-sided test at a 5% significance level is 1.65. This study source was downloaded by 100000773243632 from CourseHero.com on 03-30-2022 02:54:21 GMT -05:00 https://www.coursehero.com/file/105093617/SOPHIA-INTRO-TO-STATISTICS-UNIT-5-CHALLENGE-3pdf/  c.) The critical z-score for a left-tailed test at a 25% significance level is -0.40.  d.) The critical z-score for a two-sided test at a 3% significance level is 2.17. 5.) Spencer randomly samples the out-of-state tuition and fees for 25 public universities and found a mean of $21,032 with a standard deviation of $2,494. Using the alternative hypothesis that µ < $21,706, Spencer found a z test statistic of -1.35. Given the data provided, what is the p-value of the z-test statistic? Answer choices are rounded to the thousandths place.  a.) 0.911  b.) 0.829  c.) 0.171  d.) 0.089 6.) What value of z* should be used to construct a 90% confidence interval of a population mean? Answer choices are rounded to the hundredths place.  a.) 1.28  b.) 2.58  c.) 1.96  d.) 1.65 7.) From her purchased bags, Rory counted 110 red candies out of 550 total candies. Using a 90% confidence interval for the population proportion, what are the lower and upper limit of the interval? Answer choices are rounded to the thousandths place.  a.) Lower Limit: 0.166 Upper Limit: 0.241  b.) Lower Limit: 0.228 Upper Limit: 0.241  c.) Lower Limit: 0.172 Upper Limit: 0.228  d.) Lower Limit: 0.166 Upper Limit: 0.172 8.) A survey was conducted at local colleges around Madison, Wisconsin to find out the average height of a college student. Of 692 students surveyed, 421 replied that they were over 6 feet tall. What is the standard error? Answer choices are rounded to the hundredths place [Show More]

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