How to compute. A consumer group did a study to determine if the college students at Harvard and MIT have increased rents significantly in Cambridge compared to other towns in the Boston area. Assume that they took a sample of 49 apartments from town and that they know that the population mean is $420 and the population standard deviation of $105. What is the probability that the sample mean for the 49 houses is between $400 and $450?

If we do this exercise of taking a sample of 49 apartments fairly often, we should expect that 20% of the time our sample mean is above what value