Why do we use |v1| in the formula instead of v1?
- Let's see what happens if we use v1 instead of |v1|:
- Choose a random negative number as the initial value: - 98.
- Choose a random positive number for the end value: 45.
Formula and calculation:
(v1 - v2) / v1 =
(- 98 - 45) / - 98 =
-143 / - 98 ≈
1.459183673469 ≈
1.46
Although the absolute difference is negative: -143, the relative decrease change is positive: 1.46. By using |v1| instead of v1, the error is corrected.
The relative percent decrease change. Detailed calculations below
By multiplying a number by the fraction 100/100,
we change only the form of the result, not the result.
- 100/100 = 100% = 100 ÷ 100 = 1.
- n × 100/100 = (n × 100)/100 = (n × 100)%, any number.
The relative percent decrease change. Formula:
The relative percent decrease change =
The relative decrease change × 100/100 =
(The relative decrease change × 100)/100 =
(The relative decrease change × 100)%
Calculate the relative percent decrease change:
(999,999,999,999 - 589.5)/|999,999,999,999| =
999,999,999,409.5/999,999,999,999 =
999,999,999,409.5 ÷ 999,999,999,999 =
999,999,999,409.5 ÷ 999,999,999,999 × 100/100 =
(999,999,999,409.5 × 100 ÷ 999,999,999,999)/100 =
(99,999,999,940,950 ÷ 999,999,999,999)/100 ≈
99.99999994105/100 =
99.99999994105% ≈
100%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 999,999,999,999 to the final, end value 589.5:
Rounded off to max. 12 decimal places ≈ 99.99999994105%
Rounded off to max. 2 decimal places ≈ 100%
The absolute (actual) difference
999,999,999,999 - 589.5 = 999,999,999,409.5
By what percentage has 999,999,999,999 decreased?
Answer: By ≈ 100%
By what percentage is 589.5 smaller than 999,999,999,999?
Answer: By ≈ 100%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).