Answer:
z^3 • z^3 ? or z^3^2 ?
Step-by-step explanation:
The formula for findong the area of a circle is

Using that formula, you would do pi(9). After that, multiply pi by 9 and you would get ~28.274. Hope this helps!
Answer:
c. 18.36-21.64
Step-by-step explanation:
Using the following formulas the lower and upper limits of the interval are calculated
Lower limit = mean - (standard deviation /√sample size)* Zr
Upper limit = mean + (standard deviation /√sample size)* Zr
Zr depends on confidence interval
Zr for 90% = 1.645
then
Lower limit = 20 - (4 /√16)* 1.645 = 18.355 ≈ 18.36
Upper limit = 20 + (4 /√16)* 1.645 = 21.645 ≈ 21.64
Answer:
Step-by-step explanation:
Sorry, I couldn't draw the line. Hope it helps. :)