According to the U.S. Department of Labor, the average American household spends $639 on household supplies per year. Suppose annual expenditures on household supplies per household are uniformly distributed between the values of $261 and $1,017. (a) What is the standard deviation of this distribution? (b) What is the height of this distribution? (c) What proportion of households spend more than $900 per year on household supplies? (d) What proportion of households spend more than $1,220 per year on household supplies? (e) What proportion of households spend between $330 and $510 on household supplies?