Answer:
90
Step-by-step explanation:
The sum of squares of the deviation from mean=sum(x-xbar)²=?
x
12
6
15
9
18
12
xbar=sumx/n
xbar=(12+6+15+9+18+12)/6=72/6=12
x x-xbar (x-xbar)²
12 12-12=0 0
6 6-12=-6 36
15 15-12=3 9
9 9-12=-3 9
18 18-12=6 36
12 12-12=0 0
sum(x-xbar)²=0+36+9+9+36+0=90
So, the sum of squares of the deviations from the mean is 90.
Similar triangles that have a scale ratio other than 1 are not congruent triangles.
The true statement about the proportions of the sides is 
The scale ratio is given as: 5 : 2
And the corresponding sides are given as:
- AB and DE.
- BC and EF.
- CA and FD.
The above highlights mean that,

Hence, the true statement is 
Read more about similar triangles at:
brainly.com/question/14285697
Answer:
(a) 129600 J
(b) 81000 J
Step-by-step explanation:
The work done is given by the product of force and the displacement in the direction of force.
Force, F = 500 N
distance, d = 324 m
(a) friction force, f = 100 N
The work done is
W = (F - f) x d
W = (500 - 100) x 324
W = 129600 J
(b) Friction, f = 250 N
The work done is
W = (F - f) d
W = (500 - 250) x 324
W = 81000 J
Answer:
A
Step-by-step explanation:
A because when you find the product you need to add