Question 1206865

Margin of error ={{{ Z * (mu / sqrt(n))}}}

Where:

{{{Z}}} is {{{Z}}}-score corresponding to the desired confidence level (for a {{{80}}}% confidence level, {{{Z}}} ≈ {{{1.282}}})

a sample size {{{n=28 }}}
a sample mean x¯={{{39}}} or {{{mu=39}}}
a sample standard deviation {{{s=2}}}


Margin of error = {{{1.282 * (39 / sqrt(28))}}}

Margin of error ={{{ 1.282 * (7.37030722367993)}}}

Margin of error = {{{9.45}}}