Suppose you have a normally distributed set of data pertaining to a standardized test. the mean score is 1000 and the standard deviation is 200. what is the z-score of 900 point score? 1.5 1 0.5 â0.5

The z-score is calculated by teh equation,
                       z-score  = (X - μ) / σ
where X is the given data, μ is the mean/average and σ is the standard deviation.

From the given above,
X = 900
μ = 1000
σ = 200

Substituting the known values from the given above to the equation,
                        z-score = (900 - 1000)/ 200
                        z-score = (-100)/200
                        z-score = -1/2 = -0.5

Hence, the value of z-score is equal to -0.5. 

The correct answer is -4