The file and corresponding chart names are below: These files contain the z-scores values for the z-scores of –2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, and 2 by sex (1=male; 2=female) and half month of age. For example, 1.5 months represents 1.25-1.75 months. The only exception is birth, which represents the point at birth. A z-score tells us how many standard deviations away a value is from the mean. We use the following formula to calculate a z-score: Z-Score = (x – μ) / σ. where: x: A raw data value; μ: The mean of the dataset; σ: The standard deviation of the dataset; For example: If a value has a z-score equal to 0, then the value is equal to the mean. Transform raw scores to z-scores. Transform z-scores into new X values with desired μ and σ values. Population distribution with μ = 57 and σ = 14. Transform distribution to have μ = 50 and σ = 10. Calculate new X values for raw scores of X = 64 and X = 43. Step 1 (of 2) Transform raw scores to z-scores. z = (X – μ) / σ. Calculating and interpreting the z-score. Let’s look at an example to see how to use this formula. Example. The mean score on a standardized test was 508 with a standard deviation of 42. One test-taker’s score was 590. Find and interpret the z-score for this score. From the example, we have the following information: The mean is: \(\mu Z Score = X–X¯ Standard Deviation. where: X is a score on an original scale ( raw score) X¯ is the mean. standard deviation is the standard deviation. With this formula: The mean Z-score is Z = 0. Positive Z scores are above average. Negative Z scores are below average. JxWJM.

how to find z score