For the first one: A=pi*r^2*1/8 (1/8 becuase we are finding the area of one pane)
A=pi*16/8
A=2pi
For the second one: First do the larger circle minus the smaller circle (pretend they are whole circles)
A(larger)=pi*18^2
=324pi
A(smaller)=pi*8^2
=64pi
A=324pi-64pi =260pi
Now, a whole circle is 360 degrees so 150 degrees is 5/12 of a circle. We take 5/12 of 260pi to get the answer
260pi*5/12=340.3
A liter is equal to 1,000 mL
Meaning, the fraction would be
7.43: Let
denote the random variable for height and
for the sample mean. Then if
is the mean of
So the probability that the difference between the sample and population means does not exceed 0.5 inch is

per the empirical or 68/95/99.7 rule.
7.44: For a sample of size <em>n</em>, the sample standard deviation would be
. We want to find <em>n</em> such that

Comparing to the equation from the previous part, this means we would need

so a sample of at least 157 men would be sufficient.
Divide both sides by the numeric factor on the left side then solve x=9
I think the correct answer is D 1,-3