Elementary Statistics: A Step By Step Approach
10th Edition
ISBN: 9781259755330
Author: Allan G. Bluman
Publisher: McGraw-Hill Education
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Chapter 7.4, Problem 9E
To determine
To construct and interpret: The90% confidence interval for the population variance and standard deviation.
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Section 7.1,7.2,7.3 HW
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Question 21 of 28 (1 point) | Question Attempt: 5 of Unlimited
The proportion of phones that have more than 47 apps is 0.8783
Part: 1 / 2
Part 2 of 2
(b) Find the 70th
The 70th
percentile of the number of apps. Round the answer to two decimal places.
percentile of the number of apps is
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Hi, I need to sort out where I went wrong. So, please us the data attached and run four separate regressions, each using the Recruiters rating as the dependent variable and GMAT, Accept Rate, Salary, and Enrollment, respectively, as a single independent variable. Interpret this equation.
Round your answers to four decimal places, if necessary. If your answer is negative number, enter "minus" sign.
Equation for GMAT:
Ŷ = _______ + _______ GMAT
Equation for Accept Rate:
Ŷ = _______ + _______ Accept Rate
Equation for Salary:
Ŷ = _______ + _______ Salary
Equation for Enrollment:
Ŷ = _______ + _______ Enrollment
Question 21 of 28 (1 point) | Question Attempt: 5 of Unlimited
Dorothy ✔
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How many apps? According to a website, the mean number of apps on a smartphone in the United States is 82. Assume
the number of apps is normally distributed with mean 82 and standard deviation 30.
Part 1 of 2
(a) What proportion of phones have more than 47 apps? Round the answer to four decimal places.
The proportion of phones that have more than 47 apps is 0.8783
Part: 1/2
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Chapter 7 Solutions
Elementary Statistics: A Step By Step Approach
Ch. 7.1 - What is the difference between a point estimate...Ch. 7.1 - What information is necessary to calculate a...Ch. 7.1 - What is the margin of error?Ch. 7.1 - What is meant by the 95% confidence interval of...Ch. 7.1 - What are three properties of a good estimator?Ch. 7.1 - What statistic best estimates ?Ch. 7.1 - Find each. a. z/2 for the 99% confidence interval...Ch. 7.1 - What is necessary to determine the sample size?Ch. 7.1 - Fuel Efficiency of Cars and Trucks Since 1975 the...Ch. 7.1 - Fast-Food Bills for Drive-Thru Customers A random...
Ch. 7.1 - Overweight Men For a random sample of 60...Ch. 7.1 - Number of Jobs A sociologist found that in a...Ch. 7.1 - Number of Faculty The numbers of faculty at 32...Ch. 7.1 - Freshmen GPAs First-semester GPAs for a random...Ch. 7.1 - Carbohydrate Grams in Commercial Subs The number...Ch. 7.1 - Number of Farms A random sample of the number of...Ch. 7.1 - Gasoline Use A random sample of 36 drivers used on...Ch. 7.1 - Day Care Tuition A random sample of 50...Ch. 7.1 - Hospital Noise Levels Noise levels at various area...Ch. 7.1 - Length of Growing Seasons The growing seasons for...Ch. 7.1 - Christmas Presents How large a sample is needed to...Ch. 7.1 - Hospital Noise Levels In the hospital study cited...Ch. 7.1 - Internet Viewing A researcher wishes to estimate...Ch. 7.1 - Cost of Pizzas A pizza shop owner wishes to find...Ch. 7.1 - Water Temperature If the variance of the water...Ch. 7.1 - Undergraduate GPAs It is desired to estimate the...Ch. 7.2 - Sport Drink Decision Assume you get a new job as a...Ch. 7.2 - What are the properties of the t distribution?Ch. 7.2 - What is meant by degrees of freedom?Ch. 7.2 - Find the values for each. a. t/2 and n = 18 for...Ch. 7.2 - When should the t distribution be used to find a...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - For Exercises 5 through 20, assume that all...Ch. 7.2 - Parking Meter Revenue A one-sided confidence...Ch. 7.3 - Contracting Influenza To answer the questions, use...Ch. 7.3 - In each case, find p and q. a. n = 80 and X = 40...Ch. 7.3 - Find p and q for each situation. a. n = 60 and X =...Ch. 7.3 - Cyber Monday Shopping A survey of 1000 U.S. adults...Ch. 7.3 - Manual Transmission Automobiles In 2014, six...Ch. 7.3 - Holiday Gifts A survey of 100 Americans found that...Ch. 7.3 - Belief in Haunted Places A random sample of 205...Ch. 7.3 - Work Interruptions Research by Steelcase found the...Ch. 7.3 - Travel to Outer Space A CBS News/New York Times...Ch. 7.3 - High School Graduates Who Take the SAT The...Ch. 7.3 - Educational Television In a random sample of 200...Ch. 7.3 - Wi-Fi Access A survey of 50 students in grades 4...Ch. 7.3 - Students Who Major in Business It has been...Ch. 7.3 - Smartphone Ownership A recent survey of 349 people...Ch. 7.3 - Home Internet Access According to a study, 96% of...Ch. 7.3 - Overseas Travel A researcher wishes to be 95%...Ch. 7.3 - Widows A recent study indicated that 29% of the...Ch. 7.3 - Direct Satellite Television It is believed that...Ch. 7.3 - Obesity Obesity is defined as a body mass index...Ch. 7.3 - U.S. Fitness Guidelines According to the World...Ch. 7.3 - Diet Habits A federal report indicated that 27% of...Ch. 7.3 - Gun Control If a random sample of 600 people is...Ch. 7.3 - Survey on Politics In a study, 68% of 1015...Ch. 7.4 - Ages of Presidents at the Time of Their Deaths...Ch. 7.4 - What distribution must be used when computing...Ch. 7.4 - What assumption must be made when computing...Ch. 7.4 - Using Table G, find the values for 2 left and 2...Ch. 7.4 - Lifetimes of Wristwatches Find the 90% confidence...Ch. 7.4 - Carbohydrates in Yogurt The number of...Ch. 7.4 - Carbon Monoxide Deaths A study of...Ch. 7.4 - Pacemaker Batteries A manufacturer of pacemakers...Ch. 7.4 - Age of College Students Find the 90% confidence...Ch. 7.4 - Prob. 9ECh. 7.4 - Stock Prices A random sample of stock prices per...Ch. 7.4 - Cost of an Operation A medical researcher surveyed...Ch. 7.4 - Home Ownership Rates The percentage rates of home...Ch. 7.4 - Calories in a Standard Size Candy Bar Estimate the...Ch. 7.4 - SAT Scores Estimate the variance in mean...Ch. 7.4 - Daily Cholesterol Intake The American Heart...Ch. 7.4 - Calculator Battery Lifetimes A confidence interval...Ch. 7 - Eye Blinks A survey of 49 individuals found that...Ch. 7 - Vacation Days A U.S. Travel Data Center survey...Ch. 7 - Blood Pressure A researcher wishes to estimate...Ch. 7 - Shopping Survey A random sample of 49 shoppers...Ch. 7 - Lengths of Childrens Animated Films The lengths...Ch. 7 - Dog Bites to Postal Workers For a certain urban...Ch. 7 - Number of Credit Cards In a recent survey of 1000...Ch. 7 - Vacation Sites A U.S. Travel Data Centers survey...Ch. 7 - Prob. 7.3.9RECh. 7 - Adult Educational Activities A local county has a...Ch. 7 - Prob. 7.3.11RECh. 7 - Child Care Programs A study found that 73% of...Ch. 7 - Baseball Diameters The standard deviation of the...Ch. 7 - Cost of an Operation A medical researcher surveyed...Ch. 7 - Lifetimes of Snowmobiles A random sample of 15...Ch. 7 - Length of Childrens Animated Films Use the data...Ch. 7 - From the Data Bank choose a variable, find the...Ch. 7 - Repeat Exercise 1, using a different variable and...Ch. 7 - Repeat Exercise 1, using a proportion. For...Ch. 7 - From Data Set III in Appendix B, select a sample...Ch. 7 - From Data Set VI in Appendix B, select a sample of...Ch. 7 - Select a random sample of 20 of the record high...Ch. 7 - Determine whether each statement is true or false....Ch. 7 - Determine whether each statement is true or false....Ch. 7 - Determine whether each statement is true or false....Ch. 7 - Determine whether each statement is true or false....Ch. 7 - When a 99% confidence interval is calculated...Ch. 7 - The best point estimate of the population mean is...Ch. 7 - When the population standard deviation is unknown...Ch. 7 - Complete the following statements with the best...Ch. 7 - Complete the following statements with the best...Ch. 7 - Complete the following statements with the best...Ch. 7 - Complete the following statements with the best...Ch. 7 - Cost of Texts An irate student complained that the...Ch. 7 - Doctor Visit Costs An irate patient complained...Ch. 7 - Weights of Minivans The average weight of 40...Ch. 7 - Ages of Insurance Representatives In a study of 10...Ch. 7 - Prob. 16CQCh. 7 - Burglaries For a certain urban area, it was found...Ch. 7 - Hours Spent Studying A university dean wishes to...Ch. 7 - Prob. 19CQCh. 7 - Prob. 20CQCh. 7 - Prob. 21CQCh. 7 - Prob. 22CQCh. 7 - Prob. 23CQCh. 7 - Prob. 24CQCh. 7 - Prob. 25CQCh. 7 - Prob. 26CQCh. 7 - Critical Thinking Challenges A confidence interval...
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