The lifespans of batteries are normally distributed with a mean of 2000 hours and a standard deviation of 30 hours a. How would we know by looking at the graph if the probability of batteries with the...

The lifespans of batteries are normally distributed with a mean of 2000 hours and a standard deviation of 30 hours

a. How would we know by looking at the graph if the probability of batteries with the life span of less 1900 hours is more than 50% explain the answer

b. What percent of batteries have a lifespan that is more than 2065 hours