Answer:
Step-by-step explanation:
so you want to know the formula for the volume of a cylinder
volume (cylinder) = area of the circular base * height
2279.64 = area of a circle + height
area of a circle is 

they tell us the radius is 11 feet so r = 11
circle = 
= 38013271
2279.64 = 38013271 * height
2279.64 / 38013271 = height
5.996958 = height in feet
Answer:
5
Step-by-step explanation:
When you have an exponent inside and a exponent outside of the parentheses, you multiple them together. Since you're trying to get it equal to d^10, just divide it by 2 and you will get 5.
Answer:
a) E(X) = 71
b) V(X) = 20.59
Sigma = 4.538
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>According to a 2010 study conducted by the Toronto-based social media analytics firm Sysomos, 71% of all tweets get no reaction. That is, these are tweets that are not replied to or retweeted (Sysomos website, January 5, 2015).
</em>
<em>
Suppose we randomly select 100 tweets.
</em>
<em>a) What is the expected number of these tweets with no reaction?
</em>
<em>b) What are the variance and standard deviation for the number of these tweets with no reaction?</em>
This can be modeled with the binomial distribution, with sample size n=100 and p=0.71, as the probability of no reaction for each individual tweet.
The expected number of these tweets with no reaction can be calcualted as the mean of the binomial random variable with these parameters:

The variance for the number of these tweets with no reaction can be calculated as the variance of the binomial distribution:

Then, the standard deviation becomes:

Answer:
The volume of the solid is:
Step-by-step explanation:
GIven that :

This implies that the distance between the x-axis and the axis of the rotation = 2 units
The distance between the x-axis and the inner ring is r = (2+sec x) -2
Let R be the outer radius and r be the inner radius
By integration; the volume of the of the solid can be calculated as follows:
![V = \pi \int\limits^{\dfrac{\pi}{3}}_{\dfrac{-\pi}{3}} [(4-2)^2 - (2+ sec \ x -2)^2]dx \\ \\ \\ V = \pi \int\limits^{\dfrac{\pi}{3}}_{\dfrac{-\pi}{3}} [(2)^2 - (sec \ x )^2]dx \\ \\ \\ V = \pi \int\limits^{\dfrac{\pi}{3}}_{\dfrac{-\pi}{3}} [4 - sec^2 \ x ]dx](https://tex.z-dn.net/?f=V%20%3D%20%5Cpi%20%5Cint%5Climits%5E%7B%5Cdfrac%7B%5Cpi%7D%7B3%7D%7D_%7B%5Cdfrac%7B-%5Cpi%7D%7B3%7D%7D%20%5B%284-2%29%5E2%20-%20%282%2B%20sec%20%5C%20x%20-2%29%5E2%5Ddx%20%5C%5C%20%5C%5C%20%5C%5C%20V%20%3D%20%5Cpi%20%5Cint%5Climits%5E%7B%5Cdfrac%7B%5Cpi%7D%7B3%7D%7D_%7B%5Cdfrac%7B-%5Cpi%7D%7B3%7D%7D%20%5B%282%29%5E2%20-%20%28sec%20%5C%20x%20%29%5E2%5Ddx%20%5C%5C%20%5C%5C%20%5C%5C%20V%20%3D%20%5Cpi%20%5Cint%5Climits%5E%7B%5Cdfrac%7B%5Cpi%7D%7B3%7D%7D_%7B%5Cdfrac%7B-%5Cpi%7D%7B3%7D%7D%20%5B4%20-%20sec%5E2%20%5C%20x%20%5Ddx)
![V = \pi [4x - tan \ x]^{\dfrac{\pi}{3}}_{\dfrac{-\pi}{3}} \\ \\ \\ V = \pi [4(\dfrac{\pi}{3}) - tan (\dfrac{\pi}{3}) - 4(-\dfrac{\pi}{3})+ tan (-\dfrac{\pi}{3})] \\ \\ \\ V = \pi [4(\dfrac{\pi}{3}) - tan (\dfrac{\pi}{3}) + 4(\dfrac{\pi}{3})- tan (\dfrac{\pi}{3})] \\ \\ \\ V = \pi [8(\dfrac{\pi}{3}) - 2 \ tan (\dfrac{\pi}{3}) ]](https://tex.z-dn.net/?f=V%20%3D%20%5Cpi%20%5B4x%20-%20tan%20%5C%20%20x%5D%5E%7B%5Cdfrac%7B%5Cpi%7D%7B3%7D%7D_%7B%5Cdfrac%7B-%5Cpi%7D%7B3%7D%7D%20%20%5C%5C%20%5C%5C%20%5C%5C%20V%20%3D%20%5Cpi%20%5B4%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%20-%20tan%20%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%20-%204%28-%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%2B%20tan%20%28-%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%5D%20%5C%5C%20%5C%5C%20%5C%5C%20V%20%3D%20%5Cpi%20%5B4%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%20-%20tan%20%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%20%2B%204%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29-%20tan%20%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%5D%20%20%5C%5C%20%5C%5C%20%5C%5C%20V%20%3D%20%5Cpi%20%5B8%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%20%20-%202%20%5C%20%20tan%20%28%5Cdfrac%7B%5Cpi%7D%7B3%7D%29%20%5D)
![\mathbf{V = \pi [ \dfrac{8 \pi}{3} - 2\sqrt{3}]}](https://tex.z-dn.net/?f=%5Cmathbf%7BV%20%3D%20%5Cpi%20%5B%20%5Cdfrac%7B8%20%5Cpi%7D%7B3%7D%20-%202%5Csqrt%7B3%7D%5D%7D)