Which of the following statements best describes the location of −(−1) on a number line? (5 points)
1 answer:
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Answer:
The proportion of individuals score at most 74 points on this test is 70%.
Step-by-step explanation:
The complete question is:
Suppose that the scores on a reading ability test are normally distributed with a mean of 70 and a standard deviation of 8. What proportion of individuals score at most 74 points on this test? Round your answer to at least four decimal places.
Solution:
Let <em>X</em> represent the scores on a reading ability test.
It is provided that .
Compute the probability that an individuals score is at most 74 points on this test as follows:
Thus, the proportion of individuals score at most 74 points on this test is 70%.
In the figure attached, red circle A and red point B are the circle and external point of interest. Note that we must know where the center of circle A is. If we don't know that, there are construction techniques for finding it, but that is beyond the scope of this answer.
Step 1. Set your compass to a radius greater than half the length of segment AB. Here, we have made the radius AD.
Step 2. Draw arcs above and below the center of segment AB centered at A and B using the radius of Step 1. Here the "arc" is shown a a full (green) circle. Only the points where the arcs intersect (E and F) are of interest, so it is not necessary to draw the full circle.
Step 3. Identify the points of interesection (E and F) of the arcs of Step 2, then draw a line segment between them. This segment (EF) is the perpendicular bisector of AB. Mark point G where it intersects segment AB. As with the green circles, it is not necessary to draw the whole line EF, since we are only interested in the location of the midpoint of AB, which is point G.
Step 4. Using G as the center, and GA or GB as the radius, draw semicircle AHB. The point of intersection H is the only part of that (blue) circle of interest, so it is not necessary to draw the whole thing.
Step 5. Finish the consruction by drawing tangent line BH.
Step 1. Set your compass to a radius greater than half the length of segment AB. Here, we have made the radius AD.
Step 2. Draw arcs above and below the center of segment AB centered at A and B using the radius of Step 1. Here the "arc" is shown a a full (green) circle. Only the points where the arcs intersect (E and F) are of interest, so it is not necessary to draw the full circle.
Step 3. Identify the points of interesection (E and F) of the arcs of Step 2, then draw a line segment between them. This segment (EF) is the perpendicular bisector of AB. Mark point G where it intersects segment AB. As with the green circles, it is not necessary to draw the whole line EF, since we are only interested in the location of the midpoint of AB, which is point G.
Step 4. Using G as the center, and GA or GB as the radius, draw semicircle AHB. The point of intersection H is the only part of that (blue) circle of interest, so it is not necessary to draw the whole thing.
Step 5. Finish the consruction by drawing tangent line BH.