which of the following are true statements? 1. the standard deviation is the square root of variance 2. the standard deviation is zero only when all values are the same 3. the standard deviation is strongly affected by outliers

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.