Question

What is the Z- score Packard Bell

Answer 1

◆ Z- score

A z-score measures exactly how many standard deviations above or below the mean a data point is.

Here's the formula for calculating a z-score:

z=(data point - mean) /standard deviation

some important facts about z-scores:

A positive z-score says the data point is above average.

A negative z-score says the data point is below average.

A z-score close to 000 says the data point is close to average.

A data point can be considered unusual if its z-score is above 333 or below (-3).

Example

The grades on a history midterm at Almond have a mean of μ=85 and a standard deviation of σ =2.

Michael scored 86 on the exam.

Find the z-score for Michael's exam grade.

so, z = (his grade - mean) /standard deviation

z = (86 - 85)/2

z = 1/2 = 0.5

Michael's z-score is 0.50.50, point, 5. His grade was half of a standard deviation above the mean.