Answer:
The minimum sample size needed for each city = 922
Step-by-step explanation:
From the information given:
the objective is to find the minimum sample size needed for each city so that the margin of error not to exceed 6%.
If we take a look at the question very well:
we are only given the confidence interval of 99% and the margin of error of 6%
we were not informed or given the value or estimate of any proportions>
so we assume that:
At confidence interval of 0.99 , the level of significance = 1 - 0.99 = 0.01
The critical value for
= = 2.576
The minimum sample size needed can be calculated by using the formula :
n = 921.63
n 922
∴ The minimum sample size needed for each city = 922