Hello,
Please refer to the attachment - I can see why the formula can be simplified to n = 0.25(z / E)^2 because you get 0.25 if you make p-hat= 0.5 But I don't see how it simplifies to n = ( z / 2E)^2 ?? Why isn't the 2 a 4? Isn't 0.25 = 1/4?
Apologies, this is probably a stupid question and the answer is probably so simple....
Please refer to the attachment - I can see why the formula can be simplified to n = 0.25(z / E)^2 because you get 0.25 if you make p-hat= 0.5 But I don't see how it simplifies to n = ( z / 2E)^2 ?? Why isn't the 2 a 4? Isn't 0.25 = 1/4?
Apologies, this is probably a stupid question and the answer is probably so simple....