Introduction To Statistics And Data Analysis
6th Edition
ISBN: 9781337793612
Author: PECK, Roxy.
Publisher: Cengage Learning,
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Chapter 9.2, Problem 35E
In 2010, the online security firm Symantec estimated that 63% of computer users don’t change their passwords very often (cnet.com/news/survey-63-dont-change-passwords-very-often, retrieved November 19, 2016). Suppose that you want to carry out a new survey to estimate the proportion of students at your school who do not change their password.
- a. What is the required
sample size if you want to estimate this proportion with a margin of error of 0.05? Calculate the required sample size first using 0.63 as a preliminary estimate of p and then using the conservative value of 0.5. How do the two sample sizes compare? - b. What sample size would you recommend? Justify your answer.
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Chapter 9 Solutions
Introduction To Statistics And Data Analysis
Ch. 9.1 - Three different statistics are being considered...Ch. 9.1 - a. Why is an unbiased statistic generally...Ch. 9.1 - The report The 2016 Consumer Financial Literacy...Ch. 9.1 - The authors of the paper Influence of Biofeedback...Ch. 9.1 - Each person in a random sample of 20 students at a...Ch. 9.1 - Suppose that each of 935 smokers received a...Ch. 9.1 - Given below are the sodium contents (in mg) for...Ch. 9.1 - A random sample of n = 12 four-year-old red pine...Ch. 9.1 - A random sample of 10 houses heated with natural...Ch. 9.2 - Explain which would result in a wider large-sample...
Ch. 9.2 - Explain which would result in a wider large-sample...Ch. 9.2 - The formula used to calculate a large-sample...Ch. 9.2 - The use of the interval p(zcriticalvalue)p(1p)n...Ch. 9.2 - For each of the following combinations of sample...Ch. 9.2 - Discuss how each of the following factors affects...Ch. 9.2 - The USA TODAY Snapshot titled Social Media...Ch. 9.2 - Based on data from a survey of 1200 randomly...Ch. 9.2 - The report Parents, Teens and Digital Monitoring...Ch. 9.2 - If a hurricane was headed your way, would you...Ch. 9.2 - The USA TODAY Snapshot titled Big Bang Theory (USA...Ch. 9.2 - The article Most Dog Owners Take More Pictures of...Ch. 9.2 - The Princeton Review 2016 College Hopes and...Ch. 9.2 - The USA TODAY Snapshot titled Babys First Photo...Ch. 9.2 - The report Job Seeker Nation Study...Ch. 9.2 - USA TODAY reported that the proportion of...Ch. 9.2 - The USA TODAY Snapshot titled Have a Nice Trip...Ch. 9.2 - Business Insider reported that a study...Ch. 9.2 - In 2010, the National Football League adopted new...Ch. 9.2 - The article Most Americans Dont Understand the...Ch. 9.2 - The Gallup Organization conducts an annual survey...Ch. 9.2 - The article Hospitals Dispute Medtronic Data on...Ch. 9.2 - Based on survey of a representative sample of 1000...Ch. 9.2 - A discussion of digital ethics appears in the...Ch. 9.2 - In spite of the potential safety hazards, some...Ch. 9.2 - In 2010, the online security firm Symantec...Ch. 9.3 - Given a variable that has at distribution with the...Ch. 9.3 - The formula used to calculate a confidence...Ch. 9.3 - USA TODAY reported that the average amount of...Ch. 9.3 - Samples of two different models of cars were...Ch. 9.3 - USA TODAY reported that the average amount of...Ch. 9.3 - The paper The Effects of Adolescent Volunteer...Ch. 9.3 - Medical research has shown that repeated wrist...Ch. 9.3 - Students in a representative sample of 65...Ch. 9.3 - The paper referenced in the previous exercise also...Ch. 9.3 - Suppose that a random sample of 50 bottles of a...Ch. 9.3 - The authors of the paper Driving Performance While...Ch. 9.3 - The article The Association Between Television...Ch. 9.3 - The paper Patterns and Composition of Weight...Ch. 9.3 - Because of safety considerations, in May 2003 the...Ch. 9.3 - Example 9.3 gave the following airborne times (in...Ch. 9.3 - Consumer Reports gave the following mileage...Ch. 9.3 - Five students visiting the student health center...Ch. 9.3 - The Bureau of Alcohol, Tobacco, and Firearms...Ch. 9.3 - The formula described in this section for...Ch. 9.4 - The following quote is from the article Credit...Ch. 9.4 - Authors of the news release titled Major Gaps...Ch. 9.4 - The paper The Curious Promiscuity of Queen Honey...Ch. 9.5 - A survey on SodaHead...Ch. 9.5 - Prob. 59ECh. 9.5 - Prob. 60ECh. 9.5 - Prob. 61ECh. 9.5 - Prob. 62ECh. 9.5 - Prob. 63ECh. 9.5 - Prob. 64ECh. 9.5 - Prob. 65ECh. 9.6 - Prob. 66ECh. 9.6 - Prob. 67ECh. 9.6 - Teams in the National Football League (NFL) are...Ch. 9.6 - Prob. 69ECh. 9.6 - The Economist collects data each year on the price...Ch. 9.6 - Major League Baseball (MLB) includes two groups of...Ch. 9 - The article Write It by Hand to Make It Stick...Ch. 9 - Prob. 73CRCh. 9 - The report The 2016 Consumer Financial Literacy...Ch. 9 - The report The Politics of Climate (Pew Research...Ch. 9 - The report referenced in the previous exercise...Ch. 9 - Data from a survey of a representative sample was...Ch. 9 - A manufacturer of small appliances purchases...Ch. 9 - A manufacturer of college textbooks is interested...Ch. 9 - The confidence intervals presented in this chapter...Ch. 9 - Prob. 81CRCh. 9 - The interval from 2.33 to 1.75 captures an area of...
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