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Unformatted text preview: Introduction to Statistics PreQuiz #3
Objectives: Youi will be able to describe data using measures of variation such as the range, variance, and standard deviation Name___________________________________ Date __________________ SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Find the range for the given data. 1) A class of sixth grade students kept accurate records on the amount of time they spent playing video games during a oneweek period. The times (in hours) are listed below. Find the range. 22.9 30.3 13.6 26.3 9.4 15.5 19.7 22.5 25.0 19.6 2) 1) 2) Fred, a local mechanic, gathered the following data regarding the price, in dollars, of an oil and filter change at twelve competing service stations. Find the range. 32.95 24.95 26.95 28.95 18.95 28.95 30.95 22.95 24.95 26.95 29.95 28.95 3) Each year advertisers spend billions of dollars purchasing commercial time on network sports television. In the first 6 months of 1988, advertisers spent $1.1 billion. Who were the largest spenders? In a recent article, listed the top 10 leading spenders (in million of dollars): Company A Company B Company C Company D Company E $71.2 60.3 55.8 54 28.8 Company F Company G Company H Company I Company J $27.8 26.3 23.2 22.3 20.7 3) Calculate the sample variance. 4) The book cost (in dollars) for one semesters books are given below for a sample of five college students. Calculate the sample variance of the book costs. 260, 150, 370, 475, 275 Find the sample standard deviation for the given data. Round your final answer to one more decimal place than that used for the observations. 5) To get the best deal on a CD player, Tom called eight appliance stores and asked the cost of a specific model. The prices he was quoted are listed below: $320 $141 $285 $128 $314 $283 $337 $411 5) 4) 1 6) The normal monthly precipitation (in inches) for August is listed for 12 different U.S. cities. 3.5 1.6 2.4 3.7 4.1 3.9 1.0 3.6 4.2 3.4 3.7 2.2 Provide an appropriate response. 7) The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency distribution below summarizes the results. Find the standard deviation. Round your answer to one decimal place. Waiting time Number of (minutes) customer 7 0 4 4 8 15 11 8 12 12 16 16 0 16 20 20 24 1 8) A company had 80 employees whose salaries are summarized in the frequency distribution below. Find the standard deviation. Salary Employees 19 5,000 10,000 10,000 15,000 14 20 15,000 20,000 20,000 25,000 20 7 25,000 30,000 6) 7) 8) Find the range and standard deviation for each of the two samples, then compare the two sets of results. 9) When investigating times required for drivethrough service, the following results (in seconds) were obtained. Restaurant A 120 123 153 128 124 118 154 110 Restaurant B 115 126 147 156 118 110 145 137 9) 2 Answer Key Testname: QUIZ 3 (PREQUIZ) MEASURES OF SPREAD 1) 2) 3) 4) 5) 6) 7) 8) 9) 20.9 hr $14 361.33 15,017.50 $96.8 1.05 in. 4.6 s = 6510.7 Restaurant A: 44; 16.1 Restaurant B: 46; 16.9 Both measures indicate there is more variation in the data for restaurant B than the data for restaurant A. 3 ...
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This note was uploaded on 02/03/2012 for the course MATH 101 taught by Professor Lee during the Spring '11 term at International Institute for Higher Education.
 Spring '11
 Lee
 Statistics, Standard Deviation, Variance

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