31% of workers in the US are college graduates. You randomly select 50 workers and ask each if they graduated from college. What is the probability that at most 20 workers are college graduate.

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax