When we sample from an innite population, what happens to the standard error of the mean if the sample size is: (a) increased from 50 to 200; (b) increased from 400 to 900; (c) decreased from 225 to 25; ((1) decreased from 640 to 40? A process for making bearings produces bearings with a mean diameter of 0.5060 cm and a standard deviation of 0.0400 cm. What is the probability that the mean diameter of a sample of 100 ball bearings will be greater than 0.500 cm? If measurements of graphite spheres within an iron matrix can be modeled as a normal distribution having a standard deviation of 0.16 um, what is the probability that the mean of a sample of size 36 will differ from the population mean by no more than 006 um? The following are the elapsed time in minutes between a 911 call and the arrival of the ambulance (bearing the patient) at the hospital. Use these gures to judge the reasonableness of the claim that it takes an average of 20 minutes between the call and the patient's arrival at the hospital: 27, 15, 20, 32, 18, 26 A chemist is checking the output from a batch reaction for an undesirable byproduct, which can cause problems if present in large enough quantity. If he takes ten samples