Answer:
(a) 2%
Step-by-step explanation:
A score of 60 is 2 standard deviations below the mean (80 -2·10 = 60). The empirical rule tells you that 95% of the distribution is within 2 standard deviations of the mean. The remaining 5% is split evenly between those that are more than 2 SD above the mean and those that are more than 2 SD below the mean.
That tells you the percentage who failed is about 2.5%. The best answer choice is 2%.
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<em>Additional comment</em>
The empirical rule is a little bit sloppy, but it gets you in the ballpark. The actual percentage is closer to 2.275%.
I don’t see the questions?!
The area of the composite figure can be found by summing the whole area that made up the figure. Therefore, the area of the figure is 213.5m²
<h3>Area of a composite figure</h3>
The area of the composite figure is the sum of the area of the whole figure.
Therefore, the composite figure can be divided into 2 triangles and two rectangles.
Hence,
area of triangle1 = 1 / 2 × 10 × 13 = 65 m²
area of the triangle2 = 1 / 2 × 15 × 7 = 52.5 m²
area of the rectangle1 = 8 × 3 = 24 m²
area of rectangle2 = 7 × 6 = 42 m²
area of rectangle3 = 5 × 6 = 30 m²
Therefore,
area of the composite figure = 65 + 52.5 + 24 + 42 + 30 = 213.5 meters squared
learn more on area here: brainly.com/question/27744042
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The difference of two squares factoring pattern states that a difference of two squares can be factored as follows:
So, whenever you recognize the two terms of a subtraction to be two squares, you can factor it as the sum of the roots multiplied by the difference of the roots.
In this case, the squares are obvious: 
is the square of 
, and 
is the square of 
So, we can factor the expression as
![(x+2)^2 - (y+2)^2 = [(x+2)+(y+2)] - [(x+2)+(y+2)]](https://tex.z-dn.net/?f=%20%28x%2B2%29%5E2%20-%20%28y%2B2%29%5E2%20%3D%20%5B%28x%2B2%29%2B%28y%2B2%29%5D%20-%20%5B%28x%2B2%29%2B%28y%2B2%29%5D%20)
(the round parenthesis aren't necessary, I used them only to make clear the two terms)
We can simplify the expression summing like terms:
![(x+2)^2 - (y+2)^2 = [(x+2)+(y+2)][(x+2)-(y+2)] = (x+y+4)(x-y)](https://tex.z-dn.net/?f=%28x%2B2%29%5E2%20-%20%28y%2B2%29%5E2%20%3D%20%5B%28x%2B2%29%2B%28y%2B2%29%5D%5B%28x%2B2%29-%28y%2B2%29%5D%20%3D%20%28x%2By%2B4%29%28x-y%29%20)
