Homework Help: Statistics

Posted by Anonymous on Tuesday, February 14, 2012 at 8:26pm.

On standard IQ tests, the mean is 100 and the standard deviation is 13. The results are very close to fitting a normal curve. Suppose an IQ test is given to a very large group of people. Find the percent of people whose IQ score is between 61 and 139.

Statistics - PsyDAG, Wednesday, February 15, 2012 at 11:29am
First of all, on standard IQ tests (e.g., WISC and WAIS), SD = 15, but I will go with your data.

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion between the two Z scores. Change to percentage.

Answer this Question

Related Questions

Standard Deviation - On standard IQ tests, the mean is 100 and the standard ...
Statistics - On standard IQ tests, the mean is 110 and the standard deviation is...
Statistics - On standard IQ tests, the mean is 120 and the standard deviation is...
statistics - On standard IQ tests, the mean is 120 and the standard deviation is...
Data and statistics - If a student had a z score of 2.5 for IQ, whar is his ...
statistics - A standard IQ test has a mean of 98 and a standard deviation of 16...
statistics - If a distribution of IQ test scores has a mean of 100 and a ...
stats - Some IQ tests are standardized to a Normal model with a mean of 100 and ...
statistics - The most common intelligence quotient (IQ) scale is normally ...
statistics - The most common intelligence quotient (IQ) scale is normally ...

For Further Reading

First Name:
School Subject:
Answer: