99.7%
This is because the likelihood of a point being within 2 SDs of the mean is 99.7%.
9514 1404 393
Answer:
r = 14.5
Step-by-step explanation:
AD is the perpendicular bisector of chord EC, so is the diameter of the circle. The radius is half the diameter.
r = AD/2 = (AB +BD)/2 = (25 +4)/2 = 29/2
r = 14.5
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Segments BE and BC are 10 = √(25·4)
For this case we have the following equation:
![(2x + 3) ^ 2 + 8 (2x + 3) + 11 = 0](https://tex.z-dn.net/?f=%282x%20%2B%203%29%20%5E%202%20%2B%208%20%282x%20%2B%203%29%20%2B%2011%20%3D%200)
Let ![u = 2x + 3](https://tex.z-dn.net/?f=u%20%3D%202x%20%2B%203)
We have:
![u ^ 2 + 8u + 11 = 0](https://tex.z-dn.net/?f=u%20%5E%202%20%2B%208u%20%2B%2011%20%3D%200)
By definition, given an equation of the form ![ax ^ 2 + bx + c = 0](https://tex.z-dn.net/?f=ax%20%5E%202%20%2B%20bx%20%2B%20c%20%3D%200)
The quadratic formula, to find the solution can be written as:
![x = \frac{-b+/-\sqrt{b ^ 2-4 (a) (c)} }{2(a)}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B-b%2B%2F-%5Csqrt%7Bb%20%5E%202-4%20%28a%29%20%28c%29%7D%20%7D%7B2%28a%29%7D)
In this case we have:
![a = 1\\b = 8\\c = 11](https://tex.z-dn.net/?f=a%20%3D%201%5C%5Cb%20%3D%208%5C%5Cc%20%3D%2011)
Substituting in the quadratic formula we have:
See attached image
Answer:
Option B
The region is made up of
• a right triangle with short leg 10 m and hypotenuse 26 m
• a parallelogram with sides 40 m and 26 m (the 26-m side corresponds to the aforementioned hypotenuse)
• another triangle with two known legs of length 20 m and 26 m
Find the height of the right triangle using the Pythagorean theorem. If the height is h, then
(10 m)² + h² = (26 m)² ⇒ h² = 576 m² ⇒ h = 24 m
This height is common to all three shapes.
Now find the area of each shape.
• right triangle:
1/2 × (10 m) × (24 m) = 120 m²
• parallelogram:
(40 m) × (24 m) = 960 m²
• other triangle:
• 1/2 × (20 m) × (24 m) = 240 m²
Then the total area of the shaded region is 1320 m².
Answer:
Step-by-step explanation: