Answer:
78.88%
Step-by-step explanation:
We have been given that
The z-score formula is given by
For 
For 
Now, we find the corresponding probability from the standard z score table.
For the z score -1.25, we have the probability 0.1056
For the z score 1.25, we have the probability 0.8944
Therefore, the percent of the trees that are between 20 and 30 years old is given by
0.8944 - 0.1056
= 0.7888
=78.88%
<span>
<u><em>The correct answer is: </em></u>C 1.556.
<u><em>Explanation:</em></u>This can be found by locating the csc button on your calculator. Typically it is located as the second option below the sin button as it is the inverse function.
If you cannot locate the csc button on your calculator, you can also use </span>
<span> as csc is its inverse.
Also, it is helpful to note that some calculators have both a degrees and a radians mode for trigonometric functions. You will need to make sure that you are in degrees in order to use a calculator to solve this. </span>
Answer:
A 90
Step-by-step explanation:
multiple ways to prove this.
e.g. since the angle between the two lines from the center of the circle to the 2 tangent touching points is 90 degrees (that is the meaning of these 90 degrees here as the angle of the circle segment defined by the 2 tangent touching points and the circle center), the tangents have the same "behavior" as tan and cot = the tangents at the norm circle at 0 and 90 degrees. they hit each other outside of the circle again at 90 degrees.
another way
imagine the two right triangles of the tangents crossing point to the circle center and the tangent/circle touching points.
the Hypotenuse of each triangle is cutting the 90 degree angle of the circle segment exactly in half (due to the symmetry principle). so the angle between radius side and Hypotenuse is 90/2 = 45 degrees.
that means also the angle of such a right triangle at the tangent crossing point is 45 degrees (as the sum of all angles in a triangle must be 180, we have the remainder of 180 - 90 - 45 = 45 degrees).
the angles of both right triangles at that point are the same, and so we can add 45+45 = 90 degrees for the total angle at the tangent crossing point.
4 hours? i may be wrong
i did - 60 * 15
seems about right, since 50% would be 7.5 hours?
