Question: We know that IQs are normally distributed with a mean
We know that IQs are normally distributed with a mean of 100 and standard deviation of 15. Suppose you want to verify this, so you take 100 random samples of size four each and, for each sample, find a 95% confidence interval for the mean IQ. You expect that approximately 95 of these intervals will contain the true mean IQ (100) and approximately five of these intervals will not contain the true mean. Use simulation in Excel to see whether this is the case.
Answer to relevant QuestionsIn Section 8.9, we gave a sample size formula for confidence interval estimation of a mean. If the confidence level is 95%, then because the z-multiple is about 2, this formula is essentiallyn = 4σ2 / B2However, this ...Find a 95% confidence interval for the difference between the following two proportions: the proportion of female customers who order during the evening and the proportion of male customers who order during the evening.The file P08_65.xlsx contains data on the first 100 customers who entered a two-teller bank on Friday. All variables in this file are times, measured in minutes.a. Find a 95% confidence interval for the mean amount of time a ...Find a 95% confidence interval for Niyaki’s mean net warranty cost per unit sold (net of the $50 paid for the plan for those who purchase it). You can assume that this mean is for the first failure only; subsequent ...A producer of steel cables wants to know whether the steel cables it produces have an average breaking strength of 5000 pounds. An average breaking strength of less than 5000 pounds would not be adequate, and to produce ...
Post your question