Ace the GED Math Test 2026 – Conquer Numbers and Unlock Your Future!

To find the standard deviation of the dataset 2, 4, 4, 4, 5, 5, 7, 9, you begin by calculating the mean (average) of the dataset. First, add all the numbers together:

2 + 4 + 4 + 4 + 5 + 5 + 7 + 9 = 40.

Then, divide the total by the number of data points. In this case, there are 8 data points:

Mean = 40 / 8 = 5.

Next, you calculate the variance, which involves finding the squared differences between each data point and the mean. Calculate each squared difference:

- (2 - 5)² = (-3)² = 9

- (4 - 5)² = (-1)² = 1

- (4 - 5)² = (-1)² = 1

- (4 - 5)² = (-1)² = 1

- (5 - 5)² = (0)² = 0

- (5 - 5)² = (0)² = 0

- (7 - 5)² =