Question

I need help trying to understand how they solved this equation. Just a little confused.

Answer 1

Answer:

0.495

Explanation:

Given the expression:

$0.55-1.645\sqrt[]{\frac{0.55(1-0.55)}{220}}$

Begin by simplifying the expression under the radical (square root) sign.

$\begin{gathered} =0.55-1.645\sqrt[]{\frac{0.55(0.45)}{220}} \\ =0.55-1.645\sqrt[]{\frac{0.2475}{220}} \end{gathered}$

Using a calculator, we evaluate the radical:

$\begin{gathered} =0.55-1.645\sqrt[]{0.001125} \\ =0.494825 \\ \approx0.495\text{ (to 3 decimal places)} \end{gathered}$