On a certain exam, Tony corrected 20 papers and found the mean for his group to be 70. Alice corrected the remaining 10 papers
1 answer:
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
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The expressions for the width, W, and area, A, of the rectangle in terms of L are:
- W =
- L
- A =
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P = 2(L + W)
where L is its length and W its width
a. Given that the perimeter of the rectangle is 13 feet, then;
13 = 2(L + W)
divide through by 2
= L + W
So that;
W = - L
The required formula for the width as a function of L is: W = - L
b. Area of a rectangle can be expressed as;
A = L * W
substitute the expression for width in that of area to have
A = L * ( - L)
= L -
A =
The expression for the area A is: A =
I think the correct answer is P=3
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