Finding confidence interval

Question

A random sample of $700$ units from a large consignment showed that $200$ were damaged.how can we find the $95 \%$ confidence interval for the proportion of damaged unit in the consignment.

http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval — , Apr 15 '14 at 04:27

score 2 · Accepted Answer · answered Apr 15 '14 at 08:03

2

The confidence interval is: $\bigg(p^* - z_{\frac\alpha2}\cdot \sqrt{\dfrac{p^*\cdot (1-p^*)}{n}}, p^* + z_{\frac\alpha2}\cdot \sqrt{\dfrac{p^*\cdot (1 - p^*)}{n}}\bigg)$. Here $p^* = \dfrac{200}{700} = 0.286$, $1 - p^* = 0.714$, $n = 700$, $z_{\frac\alpha2} = 1.96$. So $C.I = (0.253, 0.319)$

answered Apr 15 '14 at 08:03

DeepSea

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thanks u so much :)@LAcarguy – sundar nataraj Apr 15 '14 at 08:54

Finding confidence interval

1 Answers1