SOLUTION: 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
Algebra ->
Probability-and-statistics
-> SOLUTION: 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
Log On
Question 366909: 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 100 Answer by robertb(5830) (Show Source):
You can put this solution on YOUR website! Without the help of further information we assume that scores on aptitude tests are normally distributed. Since the normal distribution is a CONTINUOUS distribution, P(X = 100) = 0. We can only talk about the CUMULATIVE DISTRIBUTION for a continuous distribution. Thus we can only talk about or , which in either case is equal to 0.50.
