MATH 225N Statistics Quiz Week 6, Exams of Nursing

Download MATH 225N Statistics Quiz Week 6 and more Exams Nursing in PDF only on Docsity! MATH 225N MATH Week 6 Math 225n Statistics Quiz That is correct! Answer: ( 0.10, 0.18) That is correct! MATH 225N MATH Week 6 Math 225n Statistics Quiz Week 6 Quiz Question 1 A statistics professor recently graded final exams for students in her introductory statistics course. In a review of her grading, she found the mean score out of 100 points was a x¯=77, with a margin of error of 10. Construct a confidence interval for the mean score (out of 100 points) on the final exam. Answer: (67, 87) Question 2 A random sample of adults were asked whether they prefer reading an e-book over a printed book. The survey resulted in a sample proportion of p′=0.14, with a sampling standard deviation of σp′=0.02, who preferred reading an e-book. Use the empirical rule to construct a 95% confidence interval for the true proportion of adults who prefer e- books. Question 3 The pages per book in a library are normally distributed with an unknown population mean. A MATH 225N MATH Week 6 Math 225n Statistics Quizrandom sample of books is taken and results in a 95% confidence interval of (237,293) pages. MATH 225N MATH Week 6 Math 225n Statistics Quiz Answer: (509.30, 519.18) That is correct! That is correct! MATH 225N MATH Week 6 Math 225n Statistics Quiz Question 7 A random sample of 28 statistics tutorials was selected from the past 5 years and the percentage of students absent from each one recorded. The results are given below. Assume the percentages of students' absences are approximately normally distributed. Use Excel to estimate the mean percentage of absences per tutorial over the past 5 years with 90% confidence. Round your answers to two decimal places and use increasing order. Number of Absences 13.9 16.4 12.3 13.2 8.4 4.4 10.3 8.8 4.8 HelpCopy to ClipboardDownload CSV Answer: (9.22, 11.61) Question 8 Eric is studying people's typing habits. He surveyed 525 people and asked whether they leave one space or two spaces after a period when typing. 440 people responded that they leave one space. Create a 90% confidence interval for the proportion of people who leave one space after a period. • Round your results to four decimal places. Answer: (0.8117, 0.8645) MATH 225N MATH Week 6 Math 225n Statistics QuizQuestion 9 A sample of 27 employees for the Department of Health and Human Services has the following salaries, in That is correct! Answer: 0.9804 That is correct! MATH 225N MATH Week 6 Math 225n Statistics Quiz Question 12 The graph below shows the graphs of several normal distributions, labeled A, B, and C, on the same axis. Determine which normal distribution has the smallest standard deviation. A B C Question 13 The resistance of a strain gauge is normally distributed with a mean of 100 ohms and a standard deviation of 0.3 ohms. To meet the specification, the resistance must be within the range 100±0.7 ohms. What proportion of gauges is acceptable? • Round your answer to four decimal places. Question 14 A baker knows that the daily demand for strawberry pies is a random variable that follows the normal distribution with a mean of 31.8 pies and a standard deviation of 4.5 pies. Find the demand that has an 8% probability of being exceeded. MATH 225N MATH Week 6 Math 225n Statistics Quiz • Use Excel, and round your answer to two decimal places. Answer: 38.12 That is correct! That is correct! MATH 225N MATH Week 6 Math 225n Statistics Quiz Question 15 A group of friends has gotten very competitive with their board game nights. They have found that overall, they each have won an average of 18 games, with a population standard deviation of 6 games. If a sample of only 2 friends is selected at random from the group, select the expected mean and the standard deviation of the sampling distribution from the options below. Remember to round to the nearest whole number. σx¯=6 games σx¯=3 games σx¯=4 games μx¯=18 games μx¯=3 games μx¯=9 games • Question 16 • An elementary school has a population of 635 students, 600 of whom have received the chicken pox vaccine. The school nurse wants to make sure that the school meets all state requirements for vaccinations at public schools. • Find the population proportion, as well as the mean and standard deviation of the sampling The means of That is correct! MATH 225N MATH Week 6 Math 225n Statistics Quiz A normal bell curve labeled Upper A and a normal elongated curve labeled Upper B are centered at the same point. Normal curve Upper B is narrower and above normal curve Upper A. A has the larger mean. B has the larger mean. A and B are equal. A has the larger standard deviation. B has the larger standard deviation. The standard deviations of A and B are equal. Question 19 Answer: 0.26 That is correct! MATH 225N MATH Week 6 Math 225n Statistics Quiz A tour guide company is trying to decide if it is going to increase the cost of its tours to cover its sunk costs. They find that the average sunk cost per tour is $58, with a standard deviation of $18. If they take a random sample of 36 tours, identify each of the following to help them make their decision and round to the nearest hundredth if necessary: Answer: μ = 58 σ = 18 n = 36 μ x = 58 σ x = 3 Question 20 From a recent company survey, it is known that the proportion of employees older than 55 and considering retirement is 8%. For a random sample of size 110, what is standard deviation for the sampling distribution of the sample proportions, rounded to three decimal places? Question 21 In order to estimate the average electricity usage per month, a sample of 125 residential customers were selected, and the monthly electricity usage was determined using the customers' meter readings. Assume a population variance of 12,100kWh2. Use Excel to find the 98% confidence interval for the mean electricity usage in kilowatt hours. Round your answers to two decimal places and use ascending order. Electric Usage 765 1139 714 687 1027 MATH 225N MATH Week 6 Math 225n Statistics Quiz 1109 749 799 MATH 225N MATH Week 6 Math 225n Statistics Quiz Correctly fill in the blanks in the statement above. MATH 225N MATHWeek 6 Math 225n Answer: 15.87% That is correct! Suppose Hugo types 56 words per minute in a typing test on Wednesday. The z-score when x=56 is 0.75. This z-score tells you that x=56 is 0.75 standard deviations to the right of the mean, 62. Suppose Hugo types 56 words per minute in a typing test on Wednesday. The z -score when x=56 is −0.75 . This z -score tells you that x=56 is 0.75 standard deviations to the left of the mean, 62 . Suppose Hugo types 56 words per minute in a typing test on Wednesday. The z-score when x=56 is 0.545. This z-score tells you that x=56 is 0.545 standard deviations to the right of the mean, 62. Suppose Hugo types 56 words per minute in a typing test on Wednesday. The z-score when x=56 is −0.545. This z-score tells you that x=56 is 0.545 standard deviations to the left of the mean, 62. Question 24 Lisa has collected data to find that the number of pages per book on a book shelf has a normal distribution. What is the probability that a randomly selected book has fewer than 168 pages if the mean is 190 pages and the standard deviation is 22 pages? Use the empirical rule.Enter your answer as a percent rounded to two decimal places if necessary. Question 25 Lisa has collected data to find that the number of pages per book on a book shelf has a normal distribution. What is the probability that a randomly selected book has fewer than 140 pages if the mean is 190 pages and the standard deviation is 25 pages? Use the empirical rule.Enter your answer as a percent rounded to two decimal places if necessary. That is correct! Correct answers: 2.5%