The Bank of Connecticut issues Visa and MasterCard credit cards. It is estimated that the balances on all Visa credit cards issued by the Bank of Connecticut have a mean of $850 and a standard deviation of $270. Assume that the balances on all these Visa cards follow a normal distribution.

a. What is the probability that a randomly selected Visa card issued by this bank has a balance between $1000 and $1410?

P =

b. What percentage of the Visa cards issued by this bank have a balance of $720 or more?

P =