The answer is A. After you square root both sides, you have to add 3 to both sides and then divide both sides by 4.
Supposing, for the sake of illustration, that the mean is 31.2 and the std. dev. is 1.9.
This probability can be calculated by finding z-scores and their corresponding areas under the std. normal curve.
34 in - 31.2 in
The area under this curve to the left of z = -------------------- = 1.47 (for 34 in)
1.9
32 in - 31.2 in
and that to the left of 32 in is z = ---------------------- = 0.421
1.9
Know how to use a table of z-scores to find these two areas? If not, let me know and I'll go over that with you.
My TI-83 calculator provided the following result:
normalcdf(32, 34, 31.2, 1.9) = 0.267 (answer to this sample problem)
The surface area of the balloon is 249 in².
<h3>What is the surface area of the balloon ?</h3>
A balloon has the shape of a sphere. The distance round the sphere is equal to the circumference of the sphere.
Circumference of the sphere = 2πr
Where:
- r = radius
- π = pi = 22 / 7
Radius - circumference / 2π
28 / ( 2 x 22/7) = 4.45 inches
Surface area of a sphere = 4πr²
4 x 22/7 x 4.45² = 249 in²
To learn more about the surface area of a sphere, please check: brainly.com/question/27267844
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Answer:
Option D.
Step-by-step explanation:
Let the coordinates of a point which divides the segment XY in the ratio of m : n is (x, y).
Segment X(-4, -9) and Y(4, 7) has been divided in the ratio of 2 : 6.
Therefore, x = ![\frac{[4m+n(-4)]}{m+n}=\frac{8-24}{2+6}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B4m%2Bn%28-4%29%5D%7D%7Bm%2Bn%7D%3D%5Cfrac%7B8-24%7D%7B2%2B6%7D)
= -
= -2
and y = ![\frac{[7m+n(-9)]}{m+n}=\frac{14-54}{2+6}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B7m%2Bn%28-9%29%5D%7D%7Bm%2Bn%7D%3D%5Cfrac%7B14-54%7D%7B2%2B6%7D)
= 
= -5
Therefore, the point (x, y) is (-2, -5).
Option D. will be the answer.