A recent report in the Wall Street Journal indicated a typical family of four spends $490 per month on food. Assume the distribution of food expenditures for a family of four follows the normal distribution, with a standard deviation of $90 per month. a. What percent of the families spend more than $30 but less than $490 per month on food? b. What percent of the families spend less than $430 per on food? month c. What percent of the families spend between $430 and $600 per month on food? d. What percent of the families spend between $500 and $600 per month on food? e. How many families will make up the lower 20% of the families?