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.
The main difference between a z-score and t-test is that the z-score assumes you do/don't know the actual value for the population standard deviation, whereas the t-test assumes you do/don't know the actual value for the population standard deviation. Population; sample.