Pearson Algebra 2 Common Core, 2011
PA
Pearson Algebra 2 Common Core, 2011 View details
Cumulative Standards Review

Exercise 22 Page 900

The standard deviation is the average amount by which each individual value deviates or differs from the mean of a data set.

Approximately gallons

Practice makes perfect
We are given a table showing a family's daily water usage for weeks. We want to find the standard deviation of the given data set. The standard deviation is the average amount by which each individual value deviates or differs from the mean.
In the formula, are the values of the set of data, is the mean, and is the number of values. Recall that the mean is the sum of the values divided by the number of values. Let's start by calculating their sum.
There are values in our set, so we have to divide the sum by
Let's use this value and apply the standard deviation formula to each value in the set.
Sum of Values
Finally, we need to divide by and then calculate the square root.
Therefore, we have found that the standard deviation of the family's daily water usage is approximately gallons.