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 = 329, v2 = 303.9.
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: - 54.
- Choose a random positive number for the end value: 93.
Formula and calculation:
(v1 - v2) / v1 =
(- 54 - 93) / - 54 =
-147 / - 54 ≈
2.722222222222 ≈
2.72
Although the absolute difference is negative: -147, the relative decrease change is positive: 2.72. 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:
(329 - 303.9)/|329| =
25.1/329 =
25.1 ÷ 329 =
25.1 ÷ 329 × 100/100 =
(25.1 × 100 ÷ 329)/100 =
(2,510 ÷ 329)/100 ≈
7.629179331307/100 =
7.629179331307% ≈
7.63%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 329 to the final, end value 303.9:
Rounded off to max. 12 decimal places ≈ 7.629179331307%
Rounded off to max. 2 decimal places ≈ 7.63%
The absolute (actual) difference
329 - 303.9 = 25.1
By what percentage has 329 decreased?
Answer: By ≈ 7.63%
By what percentage is 303.9 smaller than 329?
Answer: By ≈ 7.63%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).