The table below shows hypothetical per-minute cell phone charges for "pay-and-talk" service over several years.
TABLE 2-2
-Refer to Table 2-2.Assume that 2008 is used as the base year,with the index number = 100.What is the percentage change in the per-minute charge from 2011 to 2012?
A)-28.6%
B)-10.0%
C)-71.4%
D)-25.0%
E)-35.0%

Question

The table below shows hypothetical per-minute cell phone charges for "pay-and-talk" service over several years.
  TABLE 2-2
-Refer to Table 2-2.Assume that 2008 is used as the base year,with the index number = 100.What is the percentage change in the per-minute charge from 2011 to 2012?
A)-28.6% 
B)-10.0% 
C)-71.4% 
D)-25.0% 
E)-35.0%

Quizplus · Accepted Answer

To calculate the percentage change, we need to use the following formula:

Percentage change = [(new value - old value)/old value] x 100%

In this case, we want to find the percentage change in the per-minute charge from 2011 to 2012.

The per-minute charge in 2011 is $0.025, and the per-minute charge in 2012 is $0.018.

Using the formula, we get:

Percentage change = [($0.018 - $0.025)/$0.025] x 100%
Percentage change = [-$0.007/$0.025] x 100%
Percentage change = -0.28 x 100%
Percentage change = -28%

Therefore, the percentage change in the per-minute charge from 2011 to 2012 is -28%, or about -28.6% to the nearest tenth.

The best choice is A.

The Table Below Shows Hypothetical Per-Minute Cell Phone Charges for "Pay-And-Talk