Because of relatively high-interest rates, most of consumers attempt to pay off their credit card bills promptly. However, this is not always possible. An analysis of the amount of interest paid monthly by a bank's visa credit card holder reveals that the amount is normally distributed with a mean of LKR 3285 and a standard deviation of LKR 865.
i. What proportion of the bank's Visa cardholders pay more than LKR 4000 as interest?
ii. What proportion of the bank's Visa Cardholders pay between LKR 3000 and LKR 4500 as interest?
iii. What proportion of the bank's Visa Cardholders pay less than LKR 2100 as interest?
iv. What is the amount of interest payment that is exceeded by 15% of the Visa Cardholders?