how to determine the whole number standard deviation that include all data values

Question

the mean length of time to run is 30 minutes: the standard deviation is 12 minutes

30 32 45 36 38 41 30 21 60

Answer 1

Hi Brenna,

±3 standard deviations will usually contain 99% of the data. In this case 3σ=36 so 30 + 36 =96 and 30 - 36 is -6 as you can see all of the data points fall in this range.

Regards

Jim