Answer: v=w-y
Step-by-step explanation:
y+v=w
-y -y
v=w-y
Answer: range= 26, variance= 80 and standard deviation= 8.94
Step-by-step explanation:
Range = highest - lowest
Range = 146 - 120
Range= 26
Let m be mean
M=mean=sum/n
Mean=(120+134+146+127+138+133) / 6
M=798/6
M=133
The standard deviation sample formula:
S.D = sqrt( Summation of |x-m|^2 / n-1)
Let start finding:
|x-m|^2
For 1st: |120-133|^2=169
For 2nd: |134-133|^2=1
For 3rd: |146-133|^2=169
For 4th: |127-133|^2=36
For 5th: |138-133|^2=25
For 6th: |133-133|^2=0
Summation of |x-m|^2 = 400
The standard deviation formula is :
S.D = sqrt( Summation of |x-m|^2 / n-1)
S.D= sqrt(400 / 5)
S.D=sqrt(80)
S.D= 8.94
Variance = (Summation of |x-m|^2 / n-1)
Variance= 400/5
Variance= 80
Step-by-step explanation:
Area of the octagon = 2(1+√2)8=309.02 units
Answer: The average was 9 years old find the average age of both groups is 10 years old.
Step-by-step explanation:
Formula foe average : 
Given : The first group of students consists of 10 and their average age was 13 years old.
i.e.
(1)
The next group consisted of 30 students and their average was 9 years old.
i.e.
(2)
Then from (1) and (2) , the sum of both groups (first group and next group )students = 130+270 =400
Combined students of both groups (first and next group )= 10+30=40
Now , the average of both groups =

Hence, the average was 9 years old find the average age of both groups is 10 years old.