V=hpir^2
h=5
r=8
v=5pi8^2
v=5pi64
v=320pi cubic inches
The answer is 80.
You would first, divide 120 by 3.
Then, multiply 40 by 2.
Answer:
86
Step-by-step explanation:
Given that there are 30 students in class 10R and the mean marks for the entire class was 70%. Therefore, total mark of class = 70 x 30 = 2100
Given that there are 20 boys in the class and the mean marks for the boys was 62 %. Therefore, total mark of boys = 62 x 20 = 1240
To calculate the mean mark for the girls we need to find the total number of girl and total mark of girls. total number of girl = 30 - 20 (boys) = 10 total mark of girls = total mark of class - total mark of boys = 2100 - 1240 = 860 mean mark for girls = 860 / 10 = 86
Answer:
a) Var[z] = 1600
D[z] = 40
b) Var[z] = 2304
D[z] = 48
c) Var[z] = 80
D[z] = 8.94
d) Var[z] = 80
D[z] = 8.94
e) Var[z] = 320
D[z] = 17.88
Step-by-step explanation:
In general
V([x+y] = V[x] + V[y] +2Cov[xy]
how in this problem Cov[XY] = 0, then
V[x+y] = V[x] + V[y]
Also we must use this properti of the variance
V[ax+b] = 
V[x]
and remember that
standard desviation = ![\sqrt{Var[x]}](https://tex.z-dn.net/?f=%5Csqrt%7BVar%5Bx%5D%7D)
a) z = 35-10x
Var[z] = 
Var[x] = 100*16 = 1600
D[z] = 
= 40
b) z = 12x -5
Var[z] = 
Var[x] = 144*16 = 2304
D[z] = 
= 48
c) z = x + y
Var[z] = Var[x+y] = Var[x] + Var[y] = 16 + 64 = 80
D[z] = 
= 8.94
d) z = x - y
Var[z] = Var[x-y] = Var[x] + Var[y] = 16 + 64 = 80
D[z] = = 8.94
e) z = -2x + 2y
Var[z] = 4Var[x] + 4Var[y] = 4*16 + 4*64 = 320
D[z] = 
= 17.88
The three decimals that Mrs. Ibara wote were
4.15, 6.30 and 8.45
Now we have to find the other two numbers that are kept blank.
For this purpose, firstly we have to subtract the first 2 decimal numbers and find out the difference.
6.30 - 4.15 = 2.15
Now let us check the difference between the second and the third decimals.
8.45 - 6.30 = 2.15
So the difference is again the same. Then the fourth number will be
8.45 + 2.15 = 10.6
The fifth number will be
10.6 + 2.15 = 12.75
The blank spaces will be 10.6 and 12.75.
