Question

Margin of error: 0.02; confidence level: 95%; from a prior study, is estimated by the decimal equivalent of 55%. Round your answer to the nearest whole number.

Answer 1

Solution :

Given that,

= 0.55

1 - = 1 - 0.55 = 0.45

margin of error = E = 0.02

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 )

Sample size = n = (Z/2 / E)2 * * (1 - )

= (1.96 / 0.02)2 * 0.55 * 0.45

= 2376.99

Sample size =2377