Answer:
The standard error of the mean = 2
Step-by-step explanation:
Given that:
The standard deviation σ = 14
The sample size n = 49
The sample mean
= 56
The formula for calculating the standard error can be expressed as:



S.E = 2
Therefore, the standard error of the mean = 2
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
9514 1404 393
Answer:
11.6 cm
Step-by-step explanation:
As the page title tells you, the Pythagorean theorem must be applied more than once. As you know, it tells you the square of the hypotenuse is the sum of the squares of the two sides.
AD² = ED² +EA²
EA² = AD²-ED² = 7² -6² = 13
EA = √13 ≈ 3.606
__
CD² = ED² +EC²
EC² = CD² -ED² = 10² -6² = 64
EC = √64 = 8
__
The length of the horizontal diagonal is ...
AC = EA +EC = 3.6 +8 = 11.6 . . . cm
Step-by-step explanation:

<h2>-20 is the right answer.</h2>