Create a SavingsAccount class. Use a static data member annuallnterestRate to

store the annual interest rate for each of the savers. Each member of the class contains

a private data member savingsBalance indicating the amount the saver currently has on

deposit. Provide member function calculateMonthlyInterest that calculates the monthly

interest by multiplying the balance by annuallnterestRate divided by $12$; this interest

should

be

added

to savingsBalance

Provide a static member function

modifyInterestRate that sets the static annuallnterestRate to a new value.