Question

If n=180n=180 and ˆpp^ (p-hat) =0.17, find the margin of error at a 90% confidence level.

______________________________ Round to 4 places.

z-scores may be rounded to 3 places or exact using technology.

Answer 1

Solution :

Given that,

n = 180

Point estimate = sample proportion = = 0.17

1 - = 1 - 0.17 = 0.83

At 90% confidence level

= 1 - 90%  

= 1 - 0.90 =0.10

/2 = 0.05

Z/2 = Z0.05 = 1.645

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

= 1.645 (((0.17 * 0.83) / 180)

= 0.0461