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:
Step-by-step explanation:
ok :3
In the coordinate plane, the length of the line segment that connects points at (0, -1) and (-7, -2) is 7.07 units.
Correct option is A) [-13/4, 9/4] .
<u>Step-by-step explanation:</u>
Here we have following equation as |2 + 4x| = 11 or ,
. We need to solve for the value of x .Let's find out:
We know that Modulus Function is both positive & negative for particular values of x , i.e.
|2 + 4x| is positive :
⇒ 
⇒ 
⇒ 
⇒ 
|2 + 4x| is negative :
⇒ 
⇒ 
⇒ 
⇒ 
Therefore , Correct option is A) [-13/4, 9/4] .
Refer to the attached photo to see the problem worked out