Variance, standard deviation and linear variance of a discrete random variable
Let X be a rating on an integer scale
The distribution of \(X\) is given below
| \(x\) | \(\Pr(X=x)\) |
|---|---|
| \(16\) | \(\frac{1}{8}\) |
| \(17\) | \(\frac{3}{4}\) |
| \(18\) | \(\frac{1}{8}\) |
Use the table of squared-value products below. The symbol ? marks an entry to complete
| \(x\) | \(\Pr(X=x)\) | \(x^2\Pr(X=x)\) |
|---|---|---|
| \(16\) | \(\frac{1}{8}\) | ? |
| \(17\) | \(\frac{3}{4}\) | \(\frac{867}{4}\) |
| \(18\) | \(\frac{1}{8}\) | ? |
Find the variance of X. Give the exact value