Let m be mean
Mean= sum/ n
Mean= (1720+1687+1367+1614+1460+1867+1436) / 7
m= 11151 / 7
M= 1593
Mean= 1593
Standard deviation
|x-m|^2
For 1st: |1720-1593|^2=8836
For 2nd: |1687-1593|^2=10201
For 3rd: |1367-1593|^2=51076
For 4th: |1614-1593|^2=441
For 5th: |1460-1593|^2=1689
For 6th: |1867-1593|^2=75076
For 7th: |1436-1593|^2=24649
Summation of |x-m|^2 = 171968
Standard deviation sample formula is:
S.D = sqrt((summation of |x-m|^2) / n-1)
S.D=sqrt(171968/6)
S.D=sqrt(28661.33)
S.D=169.30
Standard deviation is 169.30
let the number be xy then
x + y = 12
y - x = 2 ( because y > x)
adding we get 2y = 14 so y = 7
and x = 12 - 7 = 5
So the number is 57.
ANSWER
EXPLANATION
We want to find the value of a for which the binomial, 2a-1 is smaller than the value of the binomial 7-1.2a by 7.
This means that, when we subtract 2a-1 from 7-1.2a, we should get 7.
Expand:
Group similar terms:
Divide both sides by -3.2,
Answer:
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Answer:
1716 ways
Step-by-step explanation:
Given that :
Number of entrants = 13
The number of ways of attaining first, second and third position :
The number of ways of attaining first ; only 1 person can be first ;
Using permutation :
nPr = n! ÷(n-r)!
13P1 = 13! ÷ 12! = 13
Second position :
We have 12 entrants left :
nPr = n! ÷(n-r)!
12P1 = 12! ÷ 11! = 12
Third position :
We have 11 entrants left :
nPr = n! ÷(n-r)!
11P1 = 11! ÷ 10! = 11
Hence, Number of ways = (13 * 12 * 11) = 1716 ways
