PROBLEM 13E

Out of 1000 welds that have been made on a tower, it is suspected that 15% are defective. To estimate p, the proportion of defective welds, how many welds must be inspected to have approximately 95% confidence that the maximum error of the estimate of p is 0.04?

Elements of Statistics – Chapter 7 Notes Sampling Error An error that occurs when we use sampes to estimate a population characteristic The DIFFERENCE between the POPULATION NUMERICAL INFORMATION and the SAMPLE NUMERICAL INFORMATION Sampling Distribution Choosing a sample from the original population Sample Illustrative Example EX.1) You have a population of 4 people who gave the number of meals they ate per day : 1, 3, 5, 7 SUBJECTS A B C D # OF 1 3 5 7 MEALS PER DAY SAMPLE DISTRIBUTION with a sample size of 2 A + B 1 + 3 A + C 1 + 5 A + D 1 + 7 List of all B + C