Question

calculate the percent change in the electricity bill from august to september.

expense	august	september
water	$48.00	$36.00
groceries	$150.00	$165.00
restaurant	$80.00	$96.00

round to the nearest whole percent.

Explanation:

Step1: Identify old and new values

Old value (August electricity bill) = $100, new value (September electricity bill) = $120.

Step2: Use percent - change formula

Percent change = $\frac{\text{New value}-\text{Old value}}{\text{Old value}}\times100\%=\frac{120 - 100}{100}\times100\%$.

Step3: Calculate the numerator

$120−100 = 20$.

Step4: Calculate the fraction and multiply by 100%

$\frac{20}{100}\times100\%=20\%$.

Answer:

20%