# Statistics Examples

, ,

The z-score for a value of a random variable is the number of standard deviations that falls from the mean .

The z-score converts a non-standard distribution to a standard distribution in order to find the probability of an event.

Fill in the known values.

Simplify the expression.

Simplify the numerator.

Multiply by to get .

Subtract from to get .

Divide by to get .

The z-score for a value of a random variable is the number of standard deviations that falls from the mean .

The z-score converts a non-standard distribution to a standard distribution in order to find the probability of an event.

Fill in the known values.

Simplify the expression.

Simplify the numerator.

Multiply by to get .

Subtract from to get .

Divide by to get .

Find the value in a look up table of the probability of a z-score of less than .

has an area under the curve

Find the value in a look up table of the probability of a z-score of less than .

has an area under the curve

To find the area between the two z-scores, subtract the smaller z-score value from the larger one. For any negative z-score, change the sign of the result to negative.

Multiply by to get .

Add and to get .