Question

a pizza shop charges customers based on the area of the pizza they order. the cost of a pizza in dollar represented by ( s(r) = 0.1pi r^2 ), where ( r ) is the radius of the pizza in inches. what is the diameter of a pizza that costs $26.32? round to the nearest hundredth.
○ 9.15 inches
○ 18.30 inches
○ 83.72 inches
○ 217.63 inches

Explanation:

Step1: Set cost equal to 26.32

$26.32 = 0.1 \pi r^2$

Step2: Isolate $r^2$ term

$r^2 = \frac{26.32}{0.1 \pi}$

Step3: Calculate $r^2$ value

$r^2 = \frac{26.32}{0.31416} \approx 83.778$

Step4: Solve for radius $r$

$r = \sqrt{83.778} \approx 9.153$

Step5: Find diameter ($2r$)

$d = 2 \times 9.153 \approx 18.30$

Answer:

18.30 inches