(a - 9)(a + 2)
If a train travels at the speed of 100 km how far will it travel in half an hour
2 answers:
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For this sort of problem, you need to be familiar with prefixes.
So:
megabyte = bytes
kilobyte = bytes
and a regular byte would just be
Now, you will need to do a conversion:
I'm going to explain this just in case, but we convert megabytes to regular bytes in the first half by using the information I gave you above. (In one megabyte, there are bytes!)
In the second fraction thought, remember one kilobyte is bytes. However, you usually only see one of each thing on the bottom of fractions, so you need to add a negative sign to the 3. (technically you could just do
, but I think it is more correct to do write it out how I did).
*** They do equal the same thing though! Do whichever way is easier for you!
Now, your answer should be:
kilobytes (1000 kilobytes)
Hope this helped!
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 =
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