Vocabulary on statistics

 

Calculations, the four basic operations

to calculate:
-         to subtract, a subtraction, x minus y…
-         to add up, to add sthg to sthg, an addition, a plus b…
-         to multiply by, a multiplication, f times h…
-         to divide by, a division, w over z
-         equals
 
Absolute value : number, enrollment (US)
Relative value : proportion, variation or percentage change
 
From an absolute value, you can calculate :          
- an absolute variation, (= a number of …)
- a relative variation (= +/- x%).
 
From a relative value, you can only calculate an absolute variation (= points).
 
About proportions:
 
            To calculate a proportion, you have to divide a part of a set by the set, and then multiply by 100. That way, you obtain the distribution of different parts in a set.
            The typical sentence that you have to make to express the meaning of a proportion is: “out of 100 …” .
            When you have to compare two proportions at two different dates, you will write this typical sentence: “In the year …, out of 100 …, there were …, whereas in the year …, out of 100 …, there were… . The proportion of … is higher / lower than …by x points.”
            When you have to compare two proportions of the same set at the same time, you will write this typical sentence : “In the year …, out of 100 …, there were …, whereas, out of 100 …, there were … . So the proportion of … is higher / lower than the proportion of … by x %.”
 

Nouns and verbs of comparison

 
An increase in (sthg) of (such or such)
To increase by, to fall by …
A fall in, a drop in, a decrease in (sthg) of (such or such)
To fall by, to drop by, to go down by, to decline by to decrease by … or from … to …
 
 

Variation, percentage change

 
You calculate a variation rate with the following calculation:
(The arrival value – the starting value) * 100 / the starting value
Don’t forget the sign + or – before the result in order to clearly indicate the direction of the variation.
 
The typical sentence to express the meaning of a variation rate :
“the number of … has increased / decreased by x %” or
 “if the number of … had been 100 in the year …, it would have been of (100+x) in the year…“
or “the number of … has been multiplied by (1+ x/100) between the year … and the year …(or from … to …) “.