1-20chapter stats

An environmental group at a local college is

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: dence level. A. [48.36 50.24] B. [43.27 55.33] C. [47.29 51.31] D. [47.88 50.72] E. [46.47 52.13] AACSB: Analytic Bloom's: Application Difficulty: Hard Topic: Confidence interval for population mean σ unknown 1-675 Chapter 01 - An Introduction to Business Statistics 66. An experiment was conducted to determine the effectiveness of a method designed to remove oil wastes found in soil. Three contaminated soil samples were treated. After 95 days, the percentage of contamination removed from each soil sample was measured with a mean of 49.3% and a standard deviation of 1.5%. If we wished to narrow the boundary around µ for a 98% confidence interval to within 0.5%, how many soil samples should be in our experiment. A. 437 B. 33 C. 9 D. 6 E. 3 AACSB: Analytic Bloom's: Application Difficulty: Hard Topic: Sample size determination for population mean 67. A botanist measures the heights of 16 seedlings and obtains a mean and standard deviation of 72.5 cm and 4.5 cm, respectively. Find the 95% confidence interval for the mean height of seedlings in the population form which the sample was selected. A. [62.91 82.09] B. [70.30 74.70] C. [70.10 74.90] D. [70.54 74.46] E. [71.90 73.10] AACSB: Analytic Bloom's: Application Difficulty: Medium Topic: Confidence interval for population mean σ unknown 1-676 Chapter 01 - An Introduction to Business Statistics 68. On a standard IQ test, the standard deviation is 15. How many random IQ scores must be obtained if we want to find the true population mean (with an allowable error of 0.5) and we want 97% confidence in the results? A. 4,239 B. 283 C. 212 D. 131 E. 66 AACSB: Analytic Bloom's: Application Difficulty: Medium Topic: Sample size determination for population mean 69. A manufacturer of dodge balls uses a machine to inflate its new balls to a pressure of 13.5 pounds ( = 0.1). When the machine is properly calibrated, the mean inflation pressure s 13.5 pounds, but uncontrollable factors can cause the pressure of individual dodge balls to vary. For quality control purposes, the manufacturer wishes to estimate the mean inflation pressure to within 0.025 pounds of its true value with a 99% confidence. What sample size should be used? A. 677 B. 107 C. 35 D. 27 E. 11 AACSB: Analytic Bloom's: Application Difficulty: Hard Topic: Confidence interval for population mean σ known 1-677 Chapter 01 - An Introduction to Business Statistics 70. Recently, a case of food poisoning was traced to a particular restaurant chain. The source was identified and corrective actions were taken to make sure that the food poisoning would not reoccur. Despite the response from the restaurant chain, many consumers refused to visit the restaurant for some time after the event. A survey was conducted three months after the food poisoning occurred with a sample of 319 patrons contacted. Of the 319 contacted, 29 indicated that they would not go back to the restaurant because of the potential for food poisoning Construct a 95% confidence interval for the true proportion of the market who still refuse to visit any of the restaurants in the chain three months after the event. A. [.059 .122] B. [.090 .091] C. [.000 .196] D. [.240 .339] E. [.118 .244] AACSB: Analytic Bloom's: Application Difficulty: Medium Topic: Confidence interval for population proportion 71. Recently, a case of food poisoning was traced to a particular restaurant chain. The source was identified and corrective actions were taken to make sure that the food poisoning would not reoccur. Despite the response from the restaurant chain, many consumers refused to visit the restaurant for some time after the event. A survey was conducted three months after the food poisoning occurred with a sample of 319 patrons contacted. Of the 319 contacted, 29 indicated that they would not go back to the restaurant because of the potential for food poisoning. What sample size would be needed in order to be 99% confident that the sample proportion is within .02 of ρ, the true proportion of customers who refuse to go back to the restaurant? A. 14 B. 38 C. 129 D. 1,371 E. 1,777 AACSB: Analytic Bloom's: Application Difficulty: Medium Topic: Sample size determination for population proportion 1-678 Chapter 01 - An Introduction to Business Statistics 72. In a survey of 308 adults, 17% listed jewelry among the romantic gifts men want to receive. Construct the 98% confidence interval for the proportion of all adults who include jewelry among their responses. A. [.025 .085] B. [.169 .171] C. [.120 .220] D. [.140 .200] E. [.050 .170] AACSB: Analytic Bloom's: Application Difficulty: Hard Topic: Confidence interval for population proportion 73. In a poll of 1,004 adults, 93% indicated that restaurants and bars should refuse service to patrons who have had too much to drink. Construct the 90% confidence interval for the proportion of all adults who feel the same way. A. [.078 .108] B. [.914 .946] C. [.920 .940] D. [.917 .943] E. [.910 .950] AACSB: Analytic Bloom's: Application Difficulty: Hard Top...
View Full Document

Ask a homework question - tutors are online