Fundamentals of Statistics (5th Edition)
5th Edition
ISBN: 9780134510026
Author: Sullivan
Publisher: PEARSON
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Chapter 8.1, Problem 25AYU
NW Oil Change The shape of the distribution of the time required to get an oil change at a 10-minute oil-change facility is unknown. However, records indicate that the mean time for an oil change is 11.4 minutes, and the standard deviation for oil-change time is 3.2 minutes.
- a. To compute probabilities regarding the sample mean using the normal model, what size sample would be required?
- b. What is the
probability that a random sample of n = 40 oil changes results in a sample mean time of less than 10 minutes? - c. Suppose the manager agrees to pay each employee a $50 bonus if they meet a certain goal. On a typical Saturday, the oil-change facility will perform 40 oil changes between 10 A.M. and 12 P.M. Treating this as a random sample, what mean oil-change time would there be a 10% chance of being at or below? This will be the goal established by the manager.
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Chapter 8 Solutions
Fundamentals of Statistics (5th Edition)
Ch. 8.1 - The _____ _____ of the sample mean, x, is the...Ch. 8.1 - Suppose a simple random sample of size n is drawn...Ch. 8.1 - The standard deviation of the sampling...Ch. 8.1 - True or False: The distribution of the sample...Ch. 8.1 - True or False: The distribution of the sample...Ch. 8.1 - True or False: To cut the standard error of the...Ch. 8.1 - A simple random sample of size n = 10 is obtained...Ch. 8.1 - A simple random sample of size n = 40 is obtained...Ch. 8.1 - In Problems 912, determine x and x from the given...Ch. 8.1 - In Problems 912, determine x and x from the given...
Ch. 8.1 - In Problems 912, determine x and x from the given...Ch. 8.1 - In Problems 912, determine x and x from the given...Ch. 8.1 - Answer the following questions for the sampling...Ch. 8.1 - Answer the following questions for the sampling...Ch. 8.1 - A simple random sample of size n = 49 is obtained...Ch. 8.1 - A simple random sample of size n = 36 is obtained...Ch. 8.1 - A simple random sample of size n = 12 is obtained...Ch. 8.1 - A simple random sample of size n = 20 is obtained...Ch. 8.1 - NW Gestation Period The length of human...Ch. 8.1 - Upper Leg Length The upper leg length of 20- to...Ch. 8.1 - Reading Rates The reading speed of second grade...Ch. 8.1 - Old Faithful The most famous geyser in the world....Ch. 8.1 - Rates of Return in Stocks The SP 500 is a...Ch. 8.1 - Winning Poker A very good poker player is expected...Ch. 8.1 - NW Oil Change The shape of the distribution of the...Ch. 8.1 - Time Spent in the Drive-Through The...Ch. 8.1 - Insect Fragments The Food and Drug Administration...Ch. 8.1 - Burger Kings Drive-Through Suppose that cars...Ch. 8.1 - Watching Television The amount of time Americans...Ch. 8.1 - ATM Withdrawals According to Crown ATM Network,...Ch. 8.1 - Sampling Distributions The following data...Ch. 8.1 - Sampling Distributions The following data...Ch. 8.1 - Putting It Together: Playing Roulette In the game...Ch. 8.1 - Explain what a sampling distribution is.Ch. 8.1 - State the Central Limit Theorem.Ch. 8.1 - We assume that we are obtaining simple random...Ch. 8.1 - Without doing any computation, decide which has a...Ch. 8.1 - For the three probability distributions shown,...Ch. 8.1 - Suppose Jack and Diane are each attempting to use...Ch. 8.1 - Sleepy Suppose you want to study the number of...Ch. 8.1 - Sleepy Again Suppose you want to study the number...Ch. 8.1 - Bull Markets A bull market is defined as a market...Ch. 8.2 - In a town of 500 households, 220 have a dog. The...Ch. 8.2 - The _____ _____, denoted p, is given by the...Ch. 8.2 - True or False: The population proportion and...Ch. 8.2 - True or False: The mean of the sampling...Ch. 8.2 - Describe the circumstances under which the shape...Ch. 8.2 - What happens to the standard deviation of p as the...Ch. 8.2 - In Problems 710, describe the sampling...Ch. 8.2 - In Problems 710, describe the sampling...Ch. 8.2 - In Problems 710, describe the sampling...Ch. 8.2 - In Problems 710, describe the sampling...Ch. 8.2 - A simple random sample of size n = 75 is obtained...Ch. 8.2 - A simple random sample of size n = 200 is obtained...Ch. 8.2 - Prob. 13AYUCh. 8.2 - A simple random sample of size n = 1460 is...Ch. 8.2 - Foreign Language According to a study done by...Ch. 8.2 - Are You Satisfied? According to a study done by...Ch. 8.2 - NW Marriage Obsolete? According to a study done by...Ch. 8.2 - Credit Cards According to creditcard.com, 29% of...Ch. 8.2 - Afraid to Fly According to a study conducted by...Ch. 8.2 - Having Children? The Pew Research Center recently...Ch. 8.2 - Election Prediction Exit polling is a popular...Ch. 8.2 - Acceptance Sampling A shipment of 50,000...Ch. 8.2 - Social Security Reform A researcher studying...Ch. 8.2 - Prob. 24AYUCh. 8.2 - Reincarnation Suppose 21% of all American teens...Ch. 8.2 - Assessments Consider the homeowners association...Ch. 8.2 - Airline Reservations In Chapter 6, We learned that...Ch. 8.2 - Finite Population Correction Factor In this...Ch. 8.2 - Fumbles The New England Patriots made headlines...Ch. 8 - In your own words, explain what a sampling...Ch. 8 - Prob. 2RECh. 8 - Under what conditions is the sampling distribution...Ch. 8 - Prob. 4RECh. 8 - Energy Need during Pregnancy The total energy need...Ch. 8 - Copper Tubing A machine at KA Tube Manufacturing...Ch. 8 - Number of Televisions Based on data obtained from...Ch. 8 - Entrepreneurship A Gallup survey indicated that...Ch. 8 - Advanced Degrees According to the U.S. Census...Ch. 8 - Variability in Baseball Suppose, during the course...Ch. 8 - Prob. 1CTCh. 8 - Prob. 2CTCh. 8 - The charge life of a certain lithium ion battery...Ch. 8 - A machine used for filling plastic bottles with a...Ch. 8 - Prob. 5CTCh. 8 - Prob. 6CTCh. 8 - Prob. 7CTCh. 8 - Using statistical software, generate 250 samples...Ch. 8 - Prob. 2CSCh. 8 - Prob. 3CSCh. 8 - Prob. 4CSCh. 8 - Prob. 5CSCh. 8 - Prob. 6CSCh. 8 - Prob. 7CSCh. 8 - Prob. 8CSCh. 8 - Prob. 9CSCh. 8 - Prob. 10CSCh. 8 - Prob. 11CSCh. 8 - Prob. 12CSCh. 8 - Repeat parts 11 and 12 for samples of size 20...Ch. 8 - Prob. 14CSCh. 8 - How do the averages of your sample means compare...Ch. 8 - Prob. 16CSCh. 8 - Prob. 17CSCh. 8 - Construct histograms for each column of summary...Ch. 8 - Prob. 19CS
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