Acollege-entrance exam is designed so that scores are normally distributed with a mean of 500 and a standard deviation of 100. using the eight-part symmetry of the area under a normal curve, what is the probability that a randomly chosen exam score is above 800? the probability

The probability is  0.0015

Step-by-step explanation:

We know that the average is:

The standard deviation is:

The Z-score is:

We seek to find

The Z-score is:

The score of Z = 3 means that 800 is 3 standard deviations from the mean. Then by the rule of the 8 parts of the normal curve, the area that satisfies the conficion of 3 deviations from the mean has percentage of 0.15%

So

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq

i am not sure :

step-by-step explanation: