Sunday

April 20, 2014

April 20, 2014

Posted by **m elissa** on Sunday, May 20, 2012 at 6:24pm.

Assume that the mean score on a certain aptitude test across the nation is 100, and that the standard deviation is 20 points. Find the probability that the mean aptitude test score for a randomly selected group of 150 8th graders is between 99.5 and 100.5.

Sign in

- statistics -
**PsyDAG**, Monday, May 21, 2012 at 10:38amZ = (score-mean)/SEm

SEm = SD/√n

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.

**Related Questions**

statistics probability - Alice earned a score of 940 on an IQ test.The mean test...

statistics - According to CreditReport, the mean credit score in Georgia for ...

statistics - Ram earned a score of 940 on a national achievement test. The mean ...

statistics - 7) A final exam in Statistics has a mean of 73 with a standard ...

statistics - a final exam in statistics has a mean of 73 with a standard ...

Statistics - does a raw score less than the mean correspond to a positive or ...

statistics - Assume that adults have IQ score that are normally distributed with...

social science statistics - a professor was curious to whether the students in a...

statistics-math - The mean score on a Math exam was 50% and the standard ...

Psychological Statistics - Assume that GRE scores approximate a normal curve and...