If 21% of the customers in a restaurant order fish, what is the probability that the next 3 costumers in a row will order fish?

The line plot below represents the number of letters written to overseas pen pals by the students at the waverly middle school.each x represents 10 students. how many students wrote more than 6 and fewer than 20 letters. a.250 b.240 c.230 d.220