Answer:
[0.875;0.925]
Step-by-step explanation:
Hello!
You have a random sample of n= 400 from a binomial population with x= 358 success.
Your variable is distributed X~Bi(n;ρ)
Since the sample is large enough you can apply the Central Limit Teorem and approximate the distribution of the sample proportion to normal
^ρ≈N(ρ;(ρ(1-ρ))/n)
And the standarization is
Z= ^ρ-ρ ≈N(0;1)
√(ρ(1-ρ)/n)
The formula to estimate the population proportion with a Confidence Interval is
[^ρ ± *√(^ρ(1-^ρ)/n)]
The sample proportion is calculated with the following formula:
^ρ= x/n = 358/400 = 0.895 ≅ 0.90
And the Z-value is ≅ 1.65
[0.90 ± 1.65 * √((0.90*0.10)/400)]
[0.875;0.925]
I hope you have a SUPER day!