Question

What percentage of the population has a bill less that’s $87

Answer 1

STEP - BY - STEP EXPLANATION

What to find?

Percentage of population that has a bill less than $87

Given:

mean (μ)= 70

standard deviation (σ) =8

score (x) =87

Step 1

Recall the formula to use.

$Z<\frac{X-\mu}{\sigma}$

Step 2

Substitute the values into the above.

$Z<\frac{87-70}{8}=\frac{17}{8}\approx2.13$

Step 3

Use table to find the value.

$Z<2.13=0.9834$

Step 4

Convert to percentage.

$\begin{gathered} 0.9834\times100 \\ \\ \approx98\text{ \%} \end{gathered}$

ANSWER

D) 98 %