Answer:
The confidence level is 95% or 0.95.
Explanation:
Consider the provided information.
Results of a poll stated that 40% of U.S.
If you want to test the claim at alpha = 0.05.
As we know:
Confidence level = 1 - significance level (
)
Confidence level =

Confidence level =

Therefore, the confidence level is 95% or 0.95.