Find two $z$ values, one positive and one negative but having the same absolute value, so that the areas in the two tails (ends) total $31.8 \%$. Refer to the table of values $\Theta$ Area Under the Standard Normal Distribution as needed. Round your answer to the nearest integer.
\[
z=\square \text { and } z=\square \text { }
\]

Answer

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Answer

$\boxed{z = 1 \text{ and } z = -1}$

Steps

Step 1 ：Divide the total area by 2 to find the area in each tail: $\frac{0.318}{2} = 0.159$

Step 2 ：Use a z-table or a calculator to find the corresponding z values: $z = 0.9985762706156592$ and $z = -0.9985762706156592$

Step 3 ：Round the z values to the nearest integer: $z = 1$ and $z = -1$

Step 4 ：$\boxed{z = 1 \text{ and } z = -1}$