Thread: lower bound of proportion, need lots of help with this one

1. lower bound of proportion, need lots of help with this one

For a sample of n=60, proportion p=0.5, and at a 95% confidence level, the lower bound of the proportion is ____.

95%, A=0.475
P=0.35
N=60
C=0.95, A=0475 which corresponds to z=1.65
SE= squr(0.35)(0.70)/60=0.0690
E=(1.65)(0.0690)=0.11385 or 0.121

0.121 is my answer but I'm not sure if I have set up the problem right. Thanks checking, list of possible answers are -

1. 0.229
2. 0.121
3. 0.175
4. 0.414

2. I'm not sure what you're doing but I think there's some errors somewhere.

Is this a confidence interval for proportions?.

60*(0.5)=30. What does the .35 represent?.

$E=z\sqrt{\frac{pq}{n}}$

1.96 corresponds to a 95% CI, not 1.65. 1.65 is more for a 90% CI.

But then again, I'm not sure I follow.