<span>E[Y] = 0.4·1 + 0.3·2 + 0.2·3 + 0.1·4 = 2
E[1/Y] =0.4·1/1 + 0.3·1/2 + 0.2·1/3 + 0.1·1/4 = 0.4 + 0.15 + 0.0666 + 0.025?0.64
V[Y] =E[Y2]-E[Y]2= (0.4)·12+(0.3)·22+(0.2)·32+(0.1)·42-22= 0.4+1.2+1.8+1.6-4= 5-4 = 1</span>
Ok...we got 250 people
30% are French, 35% are Americans, 20% are Germans....thats 85%.
This means 15% are from other countries
3 not from other countries...
0.85 * 0.85 * 0.85 = 0.6
0.6(250) = 150 students <===
Here are some simple equations that can be a life saver with this stuff :
vol of a sphere =

Circumference =

sorry this might not be very helpful. I haven't don't this since last year. You basically have to work backwards. so plug in 972 for V and then do (3/4)×3.14.
then take the answer u got for ^^ and divide it by 2? not sure.
Answer:
Surface area of square box cover is 4x12=48
Step-by-step explanation:
Given cylindrical cup have 2 in of radius and height of 6 in.
It is said that we need to cover the cup leaving top and bottom of cup.
To find how much material to cover:
After covering the cup, square box will be formed around the cup.
As shown in figure, Top view of square cup and box.
One face of box has length of diameter of cup = 2 in and height of box as height of cup = 6 in
Therefore, Area of one face of square box is length x height = 2 x 6 =12 
Since, Box having 4 faces
Surface area of square box cover = 4 x area of one face of box
= 4x12=48
Answer:
Step-by-step explanation:
try using each answer choise to find your answer it shoud equal 180 because all of the triangles equal that.