International travel is usually more expensive than domestic travel. A recent survey found that the average per-person cost of a 12-day international vacation is $1,755. This includes transportation, food, lodging, and entertainment.
a. If the data are normally distributed with standard deviation $390, find the percentage of vacationers who spent less than $1,200 per day. Round to the nearest hundredth of a percent.
b. Find the per-day expense for one of these travelers who had a z-score of 22.1.
c. If the data are normally distributed with standard deviation $490 instead of $390, would the answer to question 7b become lower or higher?