Answer:
The minimum sample size 'n' = 1267.78
Step-by-step explanation:
<u><em>Step:-1</em></u>
Given that the sample mean is within 12 minutes
Given that the standard deviation of the Population(σ) = 218
Level of significance = 0.05
Critical value (Z₀.₀₅) = 1.96
<u><em>Step(ii)</em></u>:-
The estimated error is defined by
√n = 35.606
squaring on both sides, we get
n = 1267.78
<u><em>Final answer:-</em></u>
The minimum sample size 'n' = 1267.78