The average amount you spend on a lunch for the week is unknown. Based on past experience, you are willing to assume that the standard deviation is...

The average amount you spend on a lunch for the week is unknown. Based on past experience, you are willing to assume that the standard deviation is about $2.00. You take a random sample of 36 lunches and apply the central limit theorem. The 68-95-99.7 rule says the probabliity is about 0.95 that x is within how much of the population mean.