1 Click Problem-2 Click Problem-3 Click Problem-4 Click Problem-5 Click Problem-6 Click Problem-7 Click Problem-8 Click Problem-9 Click Problem-10 Click Problem-11 The mean annual cost of automobile insurance is $939. Assume that the standard deviation is $245. a) What is the probability that a simple random sample of automobile insurance policies will have a sample mean within $25 of the population mean for each of the following sample sizes: 30, 50, 100, and 400? b) What is the advantage of a larger sample size when attempting to estimate the population mean? Click Problem-12 A soft drink machine is regulated so that the amount of drink it dispenses follows a normal distribution with a known standard deviation of the drinks dispensed of 20 milliliters. A random sample of 30 drinks from the machine had an average volume of 373 milliliters. Determine a 95% confidence interval for the average amount of all drinks dispensed by this machine. Click Problem-13 A soft drink machine is regulated so that the amount of drink it dispenses follows a normal distribution with a known standard deviation, and it is believed that standard deviation of the drinks dispensed is 20 milliliters. However a random sample of 30 drinks from the machine produced an average value of 373 milliliters and standard deviation of 23.4 milliliters; therefore, based on the results from sample data, there is concern that population standard deviation might be higher than what is believed. Check the validity of the concern by determining a 95% confidence interval for the standard deviation of all drinks dispensed by this machine. Click Problem-14 A Six-Sigma Black Belt is studying the performance of financial analysts from a bank using their scores on a certain aptitude test. She has collected data on a random sample of 52 analysts with an average of 85 and standard deviation of 4.2. a) Find a 90% CI for the average score of all analysts from this bank. b) Find a 90% CI on the standard deviation of the scores. Click Problem-15 A random sample of 200 consoles were examined for a scratch defect. Of the 200 samples, 22 were found to have the defect. Find a 95% confidence interval for the population proportion of consoles with this scratch defect. Click