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<(X-\mu)/(\sigma)`

Step 2

Substitute the values into the above.

`Z<(87-70)/(8)=(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*100 \\ \\ \approx98\text{ \%} \end{gathered}`

ANSWER

D) 98 %