Question

A professional hockey researcher wants to determine the true proportion of people who think fighting should not be part of the game. After surveying 800 fans at a hockey game the survey found that 212 people think fighting should not be part of the game. Construct a 90% confidence interval for the true proportion.

Answer 1

Solution :

Given that,

Point estimate = sample proportion = = x / n = 212 / 800 = 0.265

Z_/2 = 1.645

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

= 1.645 * (((0.265 * 0.735) / 800)

= 0.026

A 90% confidence interval for population proportion p is ,

- E < p < + E

0.265 - 0.026 < p < 0.265 + 0.026

0.239 < p < 0.291

(0.239 , 0.291)