You can obtain information about the mean population by taking a random sample of it and taking the average of that sample. The Law of big Numbers says that the bigger the sample, the more likely we will be closer to the real mean value. In other words, the margin of error is less likely to be big.
Answer: y ≈ 10.6 cm
Step-by-step explanation:
The cosine function relates the adjacent side to the hypotenuse in a right triangle. The side adjacent to the 20° angle is 10 cm.
cos(20°) = (10 cm)/y
y = (10 cm)/cos(20°)
y ≈ 10.6 cm

The rows add up to

, respectively. (Notice they're all powers of 2)
The sum of the numbers in row

is

.
The last problem can be solved with the binomial theorem, but I'll assume you don't take that for granted. You can prove this claim by induction. When

,

so the base case holds. Assume the claim holds for

, so that

Use this to show that it holds for

.



Notice that






So you can write the expansion for

as

and since

, you have

and so the claim holds for

, thus proving the claim overall that

Setting

gives

which agrees with the result obtained for part (c).
The domain of the function is represented by option C. All real numbers.