A sample of 9 has mean 18 and standard deviation 3. What is the t-value for testing $H_0: \mu = 20$?

Explanation

1. 01

   $t = \frac{\bar{x} - \mu}{s/\sqrt{n}} = \frac{18 - 20}{3/\sqrt{9}}$.

2. 02

   $= \frac{-2}{1} = -2$.