Answer:
The mean of the combined group is 76.67 ≈ 77
Step-by-step explanation:
- The sum of the grades in Tom's group is 20×70 = 1400
- The sum of grades in Alice's group is 10×90=900
- The sum of gradees in the combined group is =1400+900=2300
- Then the mean grade of the combined group is
where
- 2300 is the sum of the all grades in the combined group
- 30 is the total number of people in the group
Answer:
x = 37 y = 12
Step-by-step explanation:
Let x be one number
Let y = other number
x+y = 49
x-y = 25
Add the equations together
x+y = 49
x-y = 25
---------------
2x = 74
Divide by 2
2x/2 = 74/2
x =37
x+y = 49
37+y = 49
Subtract 37 from each side
37+y-37 = 49-37
y = 12
Answer:
8 ft²
Step-by-step explanation:
Since ΔEFG ~ ΔABC, they are proportionately related. Each of the corresponding sides differ by the scale factor, which shows how much bigger or smaller the new triangle is from the original triangle.
Purple = original triangle, triangle 1
Pink = new triangle, triangle 2
Find the scale factor, "k". It will be a fraction because the triangle gets smaller.
k = FG/BC = 2/3
The scale factor can be used to find a side, the height or the area of the new triangle.
Use the scale factor squared to find the area.
A₂ = (A₁)(k²)
= (18 ft²)(2/3)²
= 7.999...ft²
= 8 ft²
A rate shows how much larger or smaller one box is to the other box.
