A series of free Statistics Lectures with lessons, examples & solutions in videos.
This is the seventh page of the series of free video lessons, “Statistics Lectures”. These lectures cover the concept and use of z-scores.
Z-scores are standardized values that can be used to compare scores in different distributions.
In the United States, the average IQ is 100, with a standard deviation of 15.
What percentage of the population would you expect to have an IQ lower than 85?
What percentage of the population would you expect to have an IQ between 90 and 120?
Try the free Mathway calculator and
problem solver below to practice various math topics. Try the given examples, or type in your own
problem and check your answer with the step-by-step explanations.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.