Question

Seven students on an intramural team weigh 191 lb, 189 lb, 186 lb, 197 lb, 179 lb, 198 lb, 197 lb. what is the standard deviation of the weights of these students?

Answer 1

This is a simple question, our standard deviation represents how spread our data are, and to calculate it we need first to calculate our mean and variance as below:

To calculate our variance, we need to take the difference between each weight and the mean we just calculated and next, we square each difference and final we calculate a new mean with this values as below:

To calculate the standard deviation we just need to make the square root of our variance:

So the final answer is that the standard deviation of the weights of these students is equal to 6.48 or 6.5 (depends on the approximation).