Standard Deviation Review

What is the standard deviation?

• 5.46

• 5.76

• 143.7

• 1437

What is the standard deviation?

• 0.995

• 1.005

• 2.64

• 132

On a standardized test, Cathy had a score of 74, which was exactly 1 standard deviation below the mean. If the standard deviation for the test is 6, what is the mean score for the test?

• 71

• 77

• 80

• 68

On a standardized test, a score of 82 falls exactly 1 standard deviation below the mean. If the standard deviation for the test is 4, what is the mean score for the test?

• 78

• 84

• 86

• 80

How do you calculate the standard deviation?

• Divide the variance by 2.

• Its a long process and I can't explain it right now.

• Find the mean and multiply it by the variance.

• Take the square root of the variance.

Now, calculate the standard deviation.

• 12.1

• 21170.25

• 600.25

• 4.9

After subtracting the mean from each value in the data set, the next step is to find the sum of those differences.

• True, then square that sum.

• False. Square the differences, then find the sum.

Calculate the sum of the square of the difference. (That is, steps 2, 3, and 4 ... Σ(x - μ)²

• 145.5

• 150

• 12

Last step... What is the variance?

• 24.25

• 29.1

• 2

• 4.9

What does variance represent?

• How many different variations are in the data set.

• How the population varies compared to the sample.

• How spread out each data value is from the mean.

• The range, but with a bunch of other stuff going on.