Answer
Since we reject the Null hypothesis, there is sufficient evidence that postpartum women do not get enough sleep.
Work Step by Step
Here we have $H_{o}$: μ = 8, $H_{1}$: μ < 8, n = 151, x̅ = 7.8, s = 1.4 and α = 0.05
Using the Classical approach:
Using Table VI, we have: t = 1.655
Rejection Region < -1.655
$σ_{ x̅} = \frac{s}{\sqrt n} = \frac{1.4}{\sqrt 151} = 0.114$
$t = \frac{7.8-8}{0.114} = -1.755$
Since, 1.755 < -1.655, we will reject the Null hypothesis.
