Answer:
49
Step-by-step explanation:
Given:
Width = 0.4
Let's take the z value of 95% which is = 1.96
Let's assume population proportion p1 and p2 = 0.5
For margin of error E, the relation between the width and margin of error is 2E.
i.e 2E = 0.4
E = 0.2
To find the sample size, n, let's use the formula :
[tex]n= \frac{z^2*(p_1(1-p_1) + p_2(1-p_2))}{E^2}[/tex]
[tex] = \frac{1.96^2(0.5(1-0.5)+0.5(1-0.5))}{0.2^2}[/tex]
= 48.02
≈ 49