The random variable X has mean 12 and standard deviation 3. The random variable W is defined as W = 7+2X. What are the mean and standard deviation of W? A. The mean is 24, and the standard deviation is 6.
B. The mean is 24, and the standard deviation is 13.
C. The mean is 31, and the standard deviation is 3.
D. The mean is 31, and the standard deviation is 6.
E. The mean is 31, and the standard deviation is 13.

Mean=X=12

SD=3

W=7+2X

Mean(W)=7+2Mean(X)

Mean(W)=7+2(12)

=7+24=31

SD(W)=2SD(X)

SD(W)=2(3)=6

Ans: D

answer rather than having to add and subtract the measurements of the semi-circle, notice that the semicircle to the left of ad is actually identical in area to the blank semicircle-shaped space to the left of bc. so if we transferred the red semicircle into the blank space, we would end up with a square of side length 24 cm. the area of a square is s^2 = 24^2 = 676 cm^2.

u also answered this so i think u would know but i am here to

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