A placement exam for entrance into a math class yields a mean of 80 and a standard deviation of 10. How do you find the percentage of scores that lie between 60 and 80?
The distribution of the scores is roughly bell shaped. Use the empirical rule.
The distribution of the scores is roughly bell shaped. Use the empirical rule.
1 Answer
Jan 17, 2017
The percentage of scores that lie between
Explanation:
Let us assume that distribution is normal. As mean is
On a normal curve, it should appear as follows:
the charts/ tables show the area under the curve between
Hence, the area under the curve for
(or
Hence, the percentage of scores that lie between