According to Canadians (Leger Marketing, 2019), the average age at which one becomes old is 68 years old. Assuming that this data follows a normal distribution N(68, 7), answer the following questions

a) What is the probability of selecting someone at random that believes 75 or older is the age at which one becomes old?

b) What is the probability of selecting someone at random that believes the age at which one becomes old is between 70 and 80 years old?