Answer: 0.55567
Step-by-step explanation:
Given : A certain brand of refrigerator has a useful life that is normally distributed with mean 10 years and standard deviation 3 years. The useful lives of these refrigerators are independent.
i.e.
Let 
and 
are two randomly selected refrigerator's life whose sum will exceed third selected refrigerator 
.
So that, 
Mean 
Standard deviation =
Z-score : ![z=\dfrac{X-E[x]}{\sqrt{Var[x]}}=\dfrac{0-1}{7.0156315694}\approx-0.14](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7BX-E%5Bx%5D%7D%7B%5Csqrt%7BVar%5Bx%5D%7D%7D%3D%5Cdfrac%7B0-1%7D%7B7.0156315694%7D%5Capprox-0.14)
Now , The probability that the total useful life of two(i..e n=2) randomly selected refrigerators will exceed 1.9 times the useful life of a third randomly selected refrigerator would be :-
Hence, the required probability is 0.55567.
Answer:
(25 * 5.5) + (x * 2.9) + [(25 - x) * 4.4] = 50 * 4.5
Step-by-step explanation:
0.5 * 50Lbs. = 25 Lbs.
12.5 Lbs
12.5 Lbs.
First make sure that one of the variable has the same coefficient in each equations.
For example lets use:
y=x+3
2y=3x-1
Since neither the y's or x's are the same, we must multiply the equations to make them the same. I am going to multiply the first equation by 2 so I can eliminate the y's.
So we get:
2y=2x+3
2y=3x-1
Then we subtract the second equation from the first to eliminate the y's. So we end up with 0=-x+4 and now we solve for x
0=-x+4
x=4
Now we plug in our x into either original to get the y-value. I am using the first
y=x+3
y=4+3
So the x=4 and y=7
Hope this helps!
Answer:
D -9
Step-by-step explanation:
(g o f)(-1) = g(f(-1))
f(-1) = 
g(-4) = -4 - 5 = -9
So, (g o f)(-1) = -9
