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 = 1,047, v2 = 1,037.8.
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: - 10.
- Choose a random positive number for the end value: 58.
Formula and calculation:
(v1 - v2) / v1 =
(- 10 - 58) / - 10 =
-68 / - 10 =
6.8
Although the absolute difference is negative: -68, the relative decrease change is positive: 6.8. 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:
(1,047 - 1,037.8)/|1,047| =
9.2/1,047 =
9.2 ÷ 1,047 =
9.2 ÷ 1,047 × 100/100 =
(9.2 × 100 ÷ 1,047)/100 =
(920 ÷ 1,047)/100 ≈
0.878701050621/100 =
0.878701050621% ≈
0.88%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 1,047 to the final, end value 1,037.8:
Rounded off to max. 12 decimal places ≈ 0.878701050621%
Rounded off to max. 2 decimal places ≈ 0.88%
The absolute (actual) difference
1,047 - 1,037.8 = 9.2
By what percentage has 1,047 decreased?
Answer: By ≈ 0.88%
By what percentage is 1,037.8 smaller than 1,047?
Answer: By ≈ 0.88%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).