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 = 319, v2 = 147.1.
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: 5.
Formula and calculation:
(v1 - v2) / v1 =
(- 44 - 5) / - 44 =
-49 / - 44 ≈
1.113636363636 ≈
1.11
Although the absolute difference is negative: -49, the relative decrease change is positive: 1.11. 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:
(319 - 147.1)/|319| =
171.9/319 =
171.9 ÷ 319 =
171.9 ÷ 319 × 100/100 =
(171.9 × 100 ÷ 319)/100 =
(17,190 ÷ 319)/100 ≈
53.887147335423/100 =
53.887147335423% ≈
53.89%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 319 to the final, end value 147.1:
Rounded off to max. 12 decimal places ≈ 53.887147335423%
Rounded off to max. 2 decimal places ≈ 53.89%
The absolute (actual) difference
319 - 147.1 = 171.9
By what percentage has 319 decreased?
Answer: By ≈ 53.89%
By what percentage is 147.1 smaller than 319?
Answer: By ≈ 53.89%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).