Answer
There is sufficient evidence that the hippocampal volumes in alcoholic adolescents are less than the normal volume of 9.02 cubic centimeters.
Work Step by Step
Here we have $H_{o}$: μ = 9.02, $H_{1}$: μ < 9.02, n = 12, x̅ = 8.10, s = 0.7 and α = 0.01
From Table-VI we have:
$t_{0.01} = 2.718$
Using the classical approach:
$σ_{ x̅} = \frac{s}{\sqrt n} = \frac{0.7}{\sqrt 12} = 0.202$
$t = \frac{8.10 - 9.02}{0.202} = -4.55$
-4.55 < -2.718, we reject the Null Hypothesis.
