The mean Hb level of healthy women is 12g / dl and the SD is 1.5. What is the Z score for a woman with Hb level of 15 g/dl? (AIIMS May 2001)
The location of any element in a normal distribution can be expressed in terms of how many standard deviations it lies above or below the mean of the distribution. This is the z-score of the element. If the element lies above the mean it will have a positive z score and vice versa.
Z = X - μ
Z score = 15 – 12 = 2