An anthropologist wants to determine the percentage of all residents of California who were born outside of California. At the 90% confidence level, she wants a margin of error of no more than 1.5%. What is the smallest sample size she can safely use? (Assume there is no prior information available.) Answer: The minimum sample size is [:] people. Find the critical value za /2 that corresponds to a confidence level of 92%. Round your answer to two decimal places. Answer: 2,, f2 = I:] A quality-control expert tested a random sample of 25 Shoelaces from the Footwear Factory. The breaking strengths of the laces in the sample appeared to be normally distributed with a mean of 535 pounds, and a sample standard deviation of 32 pounds. Find the margin of error for a 99 confidence interval for the mean breaking strength of all Footwear Factory Shoelaces. Round your answer to the nearest tenth of a pound. Answer: The margin of error is [3 pounds