Answer:
The calculated value Z = 2.5 > 1.96 at 0.05 level of significance
The null hypothesis is rejected
The Alternative hypothesis is rejected
The EMS director wants to service goal of 12 minutes or less is being achieved
Step-by-step explanation:
Step(i):-
Given that the size of the random sample = 40
Given that the mean of the sample (x ⁻) = 13.25
Given that the standard deviation of the Population = 3.2 minutes
Level of significance = 0.05
The mean of the Population (μ) = 12
Step(ii):-
Null hypothesis:-H₀: (μ) = 12
Alternative Hypothesis: H₁ : μ < 12
Test statistic
[tex]Z = \frac{x^{-}-mean }{\frac{S.D}{\sqrt{n} } }[/tex]
[tex]Z = \frac{13.25-12 }{\frac{3.2}{\sqrt{40} } }[/tex]
Z = 2.5
The tabulated value Z₀.₀₅ = 1.96
The calculated value Z = 2.5 > 1.96 at 0.05 level of significance
The null hypothesis is rejected
The Alternative hypothesis is rejected
Final answer:-
The EMS director wants to service goal of 12 minutes or less is being achieved