Better Students Ask More Questions.
The Normal DistributionOn a province wide mathematics exam, the mean was 65 and the...
1 Answer | add yours
High School Teacher
Best answer as selected by question asker.
We are given that the mean was `bar(x)=65` and the standard deviation s=15. Also we know that the marks are normally distributed.
Then by the empirical normal rule we know that approximately 68% of teh marks will lie within 1 standard deviation of the mean, approximately 95% of the marks will lie within 2 standard deviations of the mean, and approximately 99.7% of the marks will lie within 3 standard deviations of the mean.
Then about 68% of the marks will be between 50 and 80, 95% will be between 35 and 95, and 99.7% will be between 20 and 110.
Posted by embizze on February 16, 2013 at 3:59 AM (Answer #1)
Join to answer this question
Join a community of thousands of dedicated teachers and students.