00:01
Hi, i'm david and i'm here to help you answer your question.
00:03
Now let me pick up your question here.
00:06
In this question we want to discuss about the conflict interval for the proportion.
00:10
Let me remind you that the conference interval for b, it would be the b heart, the sample proportion, plus and minus zan 4 over 2 times square root of the b times 1 minus b over the n.
00:25
In this formula here, this quantity here will be called the matching arrow.
00:30
In this question here we're given that the b equal to the 0 .31 and we want to have the matching error will be within 4%, so be 0 .04.
00:44
Now with the 90 % common interval, we will see that the unfa equal to the 100 % minus 90 % equal to 10%.
00:55
Therefore, unfa over 2 equal to the 5%, and equal to the 0 % and equal to the 0 % 0 .05.
01:02
So we have to look for the z under zon 05...
