Let x=25, μ=27, and σ=3.5.
To obtain the z-score, substitute the given values into the following equation and then simplify the expression.
[tex]\begin{gathered} z=\frac{x-\mu}{\sigma} \\ z=\frac{25-27}{3.5} \\ z=-\frac{2}{3.5} \\ z\approx-0.57 \end{gathered}[/tex]The 34 is 2 standard deviations away from the mean. This means we added 2σ=2(3.5)=7 to the mean which is 27.
Thus, using the 68-95-99 rule, we know that the percentage above the μ+2σ is about 2.5%. Thus, from the choices, the answer is 2%.
