percentile rank: A score that indicates the percentage of people who scored at or below a given raw score

standard normal distribution

• A normal distribution with a mean of 0 and a standard deviation of 1

z score (standard score)

• the number of standard deviations an individual score is from the mean

Standardization

• The process of putting different variables on the same scale. This process allows you to compare scores between different types of variables. Typically, to standardize variables, you calculate the mean and standard deviation for a variable

Key Concepts

Understand the unique properties of the normal curve and we can use the normal distribution as a tool

• Symmetrical, bell-shaped frequency polygon,  normal distribution  mean = median = mode

Describe what a z score is

• A number that indicates how many standard deviation units a raw score is from the mean of a distribution

Describe what a percentile rank is

• A score that indicates the percentage of people who scored at or below a given raw score