Finding Percentages in a Normal Distribution Using Z Scores and Tables

This lesson teaches how to find the percentage of a population within a certain interval using Z-scores and statistics tables. It begins with a review of the empirical rule and its limitations, then introduces Z-scores as a method to measure how far a value is from the mean. The lesson explains how to use Z-scores with statistics tables to find areas under the normal curve, converting these areas into percentages. Examples are provided to illustrate the process, including calculating the percentage of IQ scores between specific values.

What is the empirical rule and how does it relate to standard deviations from the mean?

Explain how Z-scores are calculated and what they represent.

What is the significance of the area under the normal curve being equal to 1?

How do you convert an area under the normal curve to a percentage?

How do you interpret the value obtained from a Z-score table?

Describe the process of using statistics tables to find the area under the normal curve.

What steps would you take to find the percentage of IQ scores that fall between two values?