The masses of lettuces sold at a market are normally distributed with mean 700 g and standard deviation 75 g.
(A) If a single lettuce is chosen at random, find the probability that its mass lies between 550 g and 780 g. Enter a number correct to 4 decimal places:
(B) Find the mass (in grams) exceeded by 21% of the lettuces. Enter a number correct to two decimal places:
(C) In one day, 1000 lettuces are sold. Estimate how many (of those 1000) weigh less than 620 g.
