Stat: estimate proportion

[okep]

Homework Statement

A candidate wishes to estimate the proportion, among likely voters who would vote for her on election day, with 80% margin of error less than 0.03. What sample size should she use?
Answer: 456

Homework Equations

+/- Z[phat*qhat/sqrt(n)], Z = 1.28, phat = 0.5, qhat = 0.5

The Attempt at a Solution

0.03 = 1.28 sqrt[0.5*0.5/n]
0.03/1.28 = 0.5/sqrt(n)
0.0234 = 0.5/sqrt(n)
n = [0.5/0.0234]^2
n = 456

Is the above correct. It matches with the answer 456. I don't know how to delete this question.

 

[mighty2000]

Yes, your calculation is correct. To delete your question, you can click on the three dots next to the title of your post and select "Delete". Alternatively, you can contact a moderator for assistance.