Public Health Degrees. Public health programs focus on protecting and improving the health of communities. Students in these programs learn to conduct disease-related research and analyze the effects of genetics and the environment on an individual's health.
What is a 'Z-Score'. A Z-score is a numerical measurement of a value's relationship to the mean in a group of values. If a Z-score is 0, it represents the score is identical to the mean score. Z-scores may also be positive or negative, with a positive value indicating the score is above the mean and a negative score indicating it is below the mean. Positive and negative scores also reveal the number of standard deviations the score is either above or below the mean.
Example: Find the z-score or z value of a normal variable whose value is 45 if its mean is 50 and standard deviation is 5. The value of the random variable is x = 45, and , , which means that x = 45 is 1 standard deviation below the mean since the z-value is negative 1.