Answer:
we reject H₀
We have enough evidence to claim that people in the sample are significantly more satisfied than others in general population at 95 % of CI
Step-by-step explanation:
Population mean μ₀ = 20
Sample data 18 23 24 44 19 27 23 26 25
Then:
Sample mean μ = 25,44
Sample standard deviation s = 7,14
Sample size n = 9
Hypoyhesis test:
Null hypothesis H₀ μ = μ₀
Alternative hypothesis Hₐ μ > μ₀
Significance level α = 0,05 CI = 95 %
We must develop a t-student one-tail test ( to the right ) as follows
t(c) = ??
degree of freedom df = n - 1 df = 8 and α = 0,05
Then from t-student table t(c) = 1, 8595
To calculate t(s) = ( μ - μ₀ ) / s/√n
t(s) = ( 25,44 - 20 ) * √9 / 7,14
t(s) = 5,44*3 / 7,14
t(s) = 2,29
Comparing t(c) and t(s)
t(s) > t(c)
Then t(s) is in the rejection region we reject H₀
We have enough evidence to claim that people in the sample are significantly more satisfied than others in general population at 95 % of CI
