The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean?

Step-by-step explanation:

Given that X the first-serve percentage of a tennis player in a match is normal

Std deviation =4.3%

Sample size n = 15

Std error of sample = std deviation/square root of n

=

Margin of error =Z critical value x std error

If 95% confidence is considered then we have

Z critical value=1.96

Hence margin of error =1.96(1.11)%

=2.1756%

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