A credit card company’s records show that 5% of their customers
fail to pay the minimum repayment on their credit card each month.
The company’s records also show that among their customers in the
20 to 30 age group, the amount owing on credit cards is
approximately normally distributed with mean $2,085 and standard
deviation $1,076.
a) Calculate the proportion of customers in this age group who
owe more than $3000 on their credit card.
b) If 10 customers in this age group are randomly selected, what
is the probability that the mean amount owed on the ten credit
cards is more than $3,000?