Question

In: Statistics and Probability

How large a sample n would we need to estimate p with a margin of error...

How large a sample n would we need to estimate p with a margin of error of 0.05 with 95% confidence?

Expert Solution

Solution :

Given that,

= 0.5 ( assume 0.5)

1 - = 1 - 0.5= 0.5

margin of error = E = 0.05

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 / 0.05)2 * 0.5 * 0.5

= 384.16

Sample size =385

orchestra answered 2 years ago

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