Answer:
The interval from the sample of size 400 will be approximately <u>One -half as wide</u> as the interval from the sample of size 100
Step-by-step explanation:
From the question we are told the confidence level is 95% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of
is
Generally the 95% confidence interval is dependent on the value of the margin of error at a constant sample mean or sample proportion
Generally the margin of error is mathematically represented as
Here assume that
is constant so

=> 
=> 
So let
and 
=> 
=> 
=> 
So From this we see that the confidence interval for a sample size of 400 will be half that with a sample size of 100
9+6(2^2+4)
9+6(4+4)
9+(6)(8)
9+48
=57
Because 0.09 is ten times as big as 0.009