The author of an entry-level book on using Microsoft Word has carried out a test in which 35 novices were provided with the book, a computer, and the assignment of converting a complex handwritten document with text and tables into a Microsoft Word file. The novices required an average time of 105 minutes, with a standard deviation of 20 minutes. Construct and interpret the 90% confidence interval for the population mean time it would take all such novices to complete this task.
Answer to relevant QuestionsAn office equipment manufacturer has developed a new photocopy machine and would like to estimate the average number of 81/2-by-11 copies that can be made using a single bottle of toner. For a simple random sample of 20 ...A pharmaceutical company found that 46% of 1000 U.S. adults surveyed knew neither their blood pressure nor their cholesterol level. Assuming the persons surveyed to be a simple random sample of U.S. adults, construct a 95% ...In a major industry where well over 100,000 manufacturing employees are represented by a single union, a simple random sampling of n = 100 union members finds that 57% of those in the sample intend to vote for the new labor ...In determining the necessary sample size in making an interval estimate for a population mean, it is necessary to first make an estimate of the population standard deviation. On what bases might such an estimate be made? Compared to situations where the population is either infinite or very large compared to the sample size, what effect will the finite population correction tend to have on a. The width of a confidence interval? b. The ...
Post your question