The relative decrease change. Definition:
The relative decrease change is the difference in an indicator over two periods in time, v1 - v2, relative to the value of the indicator in the earlier period, v1.
- Where:
- v1 - is called the reference value (original, initial number);
- v2 - is called the new value (the end value).
- In our case: v1 = 782, v2 = 678.7.
The relative decrease change. Formula:
The relative decrease change =
The actual change / |v1|
(v1 - v2) / |v1| =
- Legend:
- v1 - the original number
- |v1| - the positive value of v1, |v1| >= 0. By example: |10| = 10; |-10| = 10.
- v2 - the new value
- The actual change = v1 - v2
- / - the fraction bar (division)
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: - 13.
- Choose a random positive number for the end value: 53.
Formula and calculation:
(v1 - v2) / v1 =
(- 13 - 53) / - 13 =
-66 / - 13 =
5.076923076923 ≈
5.08
Although the absolute difference is negative: -66, the relative decrease change is positive: 5.08. 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:
(782 - 678.7)/|782| =
103.3/782 =
103.3 ÷ 782 =
103.3 ÷ 782 × 100/100 =
(103.3 × 100 ÷ 782)/100 =
(10,330 ÷ 782)/100 ≈
13.209718670077/100 =
13.209718670077% ≈
13.21%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 782 to the final, end value 678.7:
Rounded off to max. 12 decimal places ≈ 13.209718670077%
Rounded off to max. 2 decimal places ≈ 13.21%
The absolute (actual) difference
782 - 678.7 = 103.3
By what percentage has 782 decreased?
Answer: By ≈ 13.21%
By what percentage is 678.7 smaller than 782?
Answer: By ≈ 13.21%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).