Question

Use the sample data and confidence level to construct the confidence interval estimate of the population proportion p. n equals 600 comma x equals 120 comma 90 % confidence nothingless than p less than nothing ​(Round to three decimal places as​ needed.)

Answer 1

Solution :

Given that,

n = 600

x = 120

Point estimate = sample proportion = = x / n = 120 / 600 = 0.200

1 - = 0.800

Z_/2 = 1.645

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

= 1.645 * (((0.200 * 0.800) / 600)

= 0.027

A 90% confidence interval for population proportion p is ,

- E < p < + E

0.200 - 0.027< p < 0.200 + 0.027

0.173 < p < 0.227

The 95% confidence interval for the population proportion p is : (0.173 , 0.227)