Answer:
X=61.2
Step-by-step explanation:
x/85 = 72/100
x*100/8500 = 6120/8500
x*100 must equal 6120 therefore x must be 61.2 because 61.2 * 100 is 6120
Answer:
See the proof below.
Step-by-step explanation:
Assuming this complete question: "For each given p, let Z have a binomial distribution with parameters p and N. Suppose that N is itself binomially distributed with parameters q and M. Formulate Z as a random sum and show that Z has a binomial distribution with parameters pq and M."
Solution to the problem
For this case we can assume that we have N independent variables 
with the following distribution:
bernoulli on this case with probability of success p, and all the N variables are independent distributed. We can define the random variable Z like this:
From the info given we know that 
We need to proof that 
by the definition of binomial random variable then we need to show that:
The deduction is based on the definition of independent random variables, we can do this:
And for the variance of Z we can do this:
![Var(Z)_ = E(N) Var(X) + Var (N) [E(X)]^2](https://tex.z-dn.net/?f=%20Var%28Z%29_%20%3D%20E%28N%29%20Var%28X%29%20%2B%20Var%20%28N%29%20%5BE%28X%29%5D%5E2%20)
![Var(Z) =Mpq [p(1-p)] + Mq(1-q) p^2](https://tex.z-dn.net/?f=%20Var%28Z%29%20%3DMpq%20%5Bp%281-p%29%5D%20%2B%20Mq%281-q%29%20p%5E2)
And if we take common factor 
we got:
![Var(Z) =Mpq [(1-p) + (1-q)p]= Mpq[1-p +p-pq]= Mpq[1-pq]](https://tex.z-dn.net/?f=%20Var%28Z%29%20%3DMpq%20%5B%281-p%29%20%2B%20%281-q%29p%5D%3D%20Mpq%5B1-p%20%2Bp-pq%5D%3D%20Mpq%5B1-pq%5D)
And as we can see then we can conclude that
<span> we know the length of the cable is 9m.
That means the magnitude of </span><span><span>r<span><span><span>AB</span></span><span></span></span></span>=9</span><span>m.
The unit vector, denoted u, is each of </span><span>r<span><span><span>AB</span></span><span></span></span></span><span> divided by the magnitude.
</span>u=<span>(<span><span>x/9</span><span></span></span>i−<span>y/9<span></span></span>j−<span>z/9<span></span></span>k<span>)
</span></span><span>We can also figure out the unit vector of F.
</span>u=(350i - 250j - 450k)/√(350² +(-250)² +(-450)²)
u=0.562i−0.401j−0.723<span>k
</span>
<span>Force F is directed from point A to B, then both unit vectors must be equal.
Therefore
</span>(x/9i−y/9j−z/9k)=0.562i−0.401j−0.723k
<span>We can now solve for each term
x/9=0.562----- > x=5.058 m
-y/9=-0.401--------- > y=3.609 m
-z/9=-0.723------- > z=6.507 m
The answer is
the coordinates of point a
(5.058,3.609,6.507)
</span>
The difference (subtraction) of 6 times a number (x represents number) and 7. This gives us 6x-7. That is equal to five times (multiplication) the sum (addition) of the number, x, and 4. This gives you = 5(x+4) and combined gives us B, 6x-7=5(x+4).
