Interval Frequency The lives (in hours of continuous use) of 100 randomly selected 6.95 -7.45 flashlight batteries are: 7.45-7.95 CO NO 7.95 -8.45 19 8.45 -8.95 39 8.95 - 9.45 19 9.45 - 9.95 10 9.95 - 10.45 3 a. Find the mean of the battery lives. hrs (Type an integer or a decimal. Round to two decimal places.) b. Find the standard deviation of the battery lives. hrs (Type an integer or a decimal. Round to two decimal places.)