1. According to the growth chart that doctors use as reference, the heights of two-year ?old boys are normally distributed with mean = 34.5 inches and standard deviation = 1.3 inches. For a random sample of 6 two-year-old boys, find the probability that the sample mean will be between 34.1 and 35.2 inches. 2. The time that customers take to complete their transaction at a money machine is a random variable with mean = 2 minutes and standard deviation = 0.6 minute. Find the probability that a random sample of 50 customers will take between 90 and 112.5 minutes to complete all their transactions. That is, find the probability that X will be between 1.8 and 2.25 minutes. 3.Data on the average weekly earnings were obtained from a survey of 50 nonsupervisory production workers in the mining industry. The sample mean and standard deviation were found to be $630 and $35, respectively. Estimate the true mean weekly earnings and determine the 95% error margin.
Paper#6709 | Written in 18-Jul-2015Price : $25