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: - 16.
- Choose a random positive number for the end value: 30.
Formula and calculation:
(v1 - v2) / v1 =
(- 16 - 30) / - 16 =
-46 / - 16 =
2.875 ≈
2.88
Although the absolute difference is negative: -46, the relative decrease change is positive: 2.88. 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 - 591.7)/|999,999,999,999| =
999,999,999,407.3/999,999,999,999 =
999,999,999,407.3 ÷ 999,999,999,999 =
999,999,999,407.3 ÷ 999,999,999,999 × 100/100 =
(999,999,999,407.3 × 100 ÷ 999,999,999,999)/100 =
(99,999,999,940,730 ÷ 999,999,999,999)/100 ≈
99.99999994083/100 =
99.99999994083% ≈
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 591.7:
Rounded off to max. 12 decimal places ≈ 99.99999994083%
Rounded off to max. 2 decimal places ≈ 100%
The absolute (actual) difference
999,999,999,999 - 591.7 = 999,999,999,407.3
By what percentage has 999,999,999,999 decreased?
Answer: By ≈ 100%
By what percentage is 591.7 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).