Question

Why i cannot construct a 100% interval confidence in statistics and instead of this we construct 90%,95% or 99% in most cases?

Answer 1

We can never construct a 100% confidence interval because we can never be 100% confident or sure about anything. There is always some error due to which we cant be 100% certain about the result.

We also know that the margin of error increases with increase in confidence level, so margin of error will be maximum when using 100% confidence interval. Therefore, it is not good to use 100% confidence interval because it will give us maximum amount of margin of error