Question

Did you get your 8 hours of sleep last night?" is a common question. In a recent survey of 151 postpartum women, the folks at the National Sleep Foundation found that the mean sleep time was 7.8 hours, with a standard deviation of 1.4 hours. Does the evidence suggest that postpartum women do not get enough sleep? Use α = 0.05 level of significance.

Answer 1

There is evidence to suggest that postpartum women do not get enough sleep

Explanation:

Given that in a recent survey of 151 postpartum women, the folks at the National Sleep Foundation found that the mean sleep time was 7.8 hours, with a standard deviation of 1.4 hours.

`H_0: \bar x =8\\H_a: \bar x <8`

(left tailed test at 5% significance)

Mean difference = -0.20

Std error of sample =
`(s)/(√(n) ) \\=(1.4)/(√(151) ) \\=0.114`

Test statistic t = mean difference/std error =

= -1.76

df = 150

p value one tailed = 0.0402

Since p < alpha, we reject H0

There is evidence to suggest that postpartum women do not get enough sleep