Question

If n equals=200 and X equals=70construct a 99%confidence interval estimate for the population proportion

nothingless than or equals≤piπless than or equals≤nothing

Answer 1

Solution :

Given that,

Point estimate = sample proportion = = x / n = 70 / 200 = 0.350

1 - = 1 - 0.350 = 0.65

Z/2 = 2.576

Margin of error = E = Z / 2 * (( * (1 - )) / n)

= 2.576 * (((0.350 * 0.65) / 200)

Margin of error = E = 0.087

A 99% confidence interval for population proportion p is ,

- E < p < + E

0.350 - 0.087 < p < 0.350 + 0.087

0.263 < p < 0.437