Answer:
Hence when C.I. is 80% then Margin of error will be 1.9591%
Step-by-step explanation:
Given:
1st Margin of error(MOE)=3%
1st C.I.=95%
2nd C.I.=80%
To Find:
MOE at 80%
Solution:
The proportion is 64 % i.e. is constant for both MOE
Proportion is given by (P),
P=x/n
Where x= favors congressional terms
n= total voters or sampled voters.
There values are same or constant.
i.e standard deviation is also constant
Now Formula for MOE is given by
here Z is value for confidence interval
MOE is directly proportional to the Z-value
So
... where k is proportionality constant.
....ratio is constant
So , for 95 % Z=1.96 and for 80% Z=1.28
%