3.5 cubic centimeters is also equivalent to 3.5 ml
Answer: 
Step-by-step explanation:
The confidence interval for the difference of two population proportion is given by :-

Given : The first sample consists of 20 people with 9 having a common attribute.
Here,
, 
, 
Significance level : 
Critical value : 
A 95% confidence interval for the difference of two population proportion will be :-
