Two studies estimate the same proportion. Study 1: n = 100. Study 2: n = 400. Both have p̂ = 0.5.
The width of Study 2's CI compared to Study 1's is:
- A
Twice as wide
- B
One-fourth as wide
- Ccheck_circle
Half as wide
- D
The same
Explanation
SE ∝ 1/sqrt(n); n increases by factor 4, SE halved, so width halved.