a choices are 68% 75% 95% and 99.7% please help

The batteries from a certain manufacturer have a mean lifetime of 830 hours, with a standard deviation of 90 hours. Assuming that the lifetimes are normally distributed, complete the following statements. (a) Approximately ? |of the batteries have lifetimes between 560 hours and 1100 hours. (b) Approximately 95% of the batteries have lifetimes between hours and hours . X 5 2