The coefficient of variation is 20%
The lower limit is 9 and the upper limit is 21
<h3 /><h3>How to calculate the coefficient of variation</h3>
Given the following parameters
- Sample mean "x" = 15
- standard deviation 's" = 3
The coefficient of variation is expressed as:
coefficient of variation = s/x * 100
coefficient of variation = 3/15 * 100
coefficient of variation = = 20%
Hence the coefficient of variation is 20%
The formula for the Chebyshev interval is given as:

Get the value of k using the formula below:

Get the required interval

Hence the lower limit is 9 and the upper limit is 21
Learn more on confidence intervals here: brainly.com/question/15712887