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
Answer:
Think of y = mx + b,
With y = x + 3, m = 1 so the slope is one, and b = 3 which is the y-intercept, so plot the point (0,3) on the y-axis.
To find the next point to plot go up 1 and over to the right 1 because slope is rise over run.
With y = x, the slope is still 1, but there is no y-intercept, so you plot the point (0,0), and to find the next point on that line, go up 1 and over the right 1 because m=1
9514 1404 393
Answer:
1/4 mile
Step-by-step explanation:
The length and width of a square are the same.
The length is 1/4 mile, so the width of the park is 1/4 mile.
D = (5-1)/(13-(-3)) = 0.25
f(13) = 13d + x = 13 * 0.25 + a = 3.25 + a = 5
a = 1.75
f(x) = 1.75 + 0.25x
3/5 x 2 = 6/10
6/10>4/10 sorry if that’s not right you didn’t really show us the answer choices
