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 = 278, v2 = 32.3.
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: - 44.
- Choose a random positive number for the end value: 93.
Formula and calculation:
(v1 - v2) / v1 =
(- 44 - 93) / - 44 =
-137 / - 44 ≈
3.113636363636 ≈
3.11
Although the absolute difference is negative: -137, the relative decrease change is positive: 3.11. 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:
(278 - 32.3)/|278| =
245.7/278 =
245.7 ÷ 278 =
245.7 ÷ 278 × 100/100 =
(245.7 × 100 ÷ 278)/100 =
(24,570 ÷ 278)/100 ≈
88.381294964029/100 =
88.381294964029% ≈
88.38%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 278 to the final, end value 32.3:
Rounded off to max. 12 decimal places ≈ 88.381294964029%
Rounded off to max. 2 decimal places ≈ 88.38%
The absolute (actual) difference
278 - 32.3 = 245.7
By what percentage has 278 decreased?
Answer: By ≈ 88.38%
By what percentage is 32.3 smaller than 278?
Answer: By ≈ 88.38%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).