Question

A survey of British 1,243 folks showed that 45% of respondents believed the Queen had done a good job on the throne. What is the margin of the error for this estimate with 95% confidence? Round to two decimal places

post work please, make sure answer is clear and legible.

Answer 1

Solution :

Given that,

n = 1243

Point estimate = sample proportion = =0.45

1 -   = 1- 0.45 =0.55

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96   ( Using z table )

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

= 1.96 (((0.45*0.55) /1243 )

E = 0.03

Margin of error = E = 0.03