A recent report indicated an average family of four (2 parents and 2 children under the age of 16), spends $500 per month on gasoline. Assume the distribution of gasoline consumption expenditures for a family of four (2 parents and 2 children under the age of 16) follows the normal distribution, with a standard deviation of $75 per month. Round your answer to 2 decimals. Please add explanation to support your answer for each question.
a. What percent of families spend more than $450 but less than $500?
b. What percent of the families spend less than $425?
c. What percent spends between $425 and $575?
d. What percent spends between $575 and $650?