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.
If we pay $8.28 for 18 stamps we can find the price of one stamp by dividing by 18.
So, the price of one stamp will be
$8.28 / 18 = $ 0.46
To find the price of 12 stamps we have to multiply by 12 and finally find
$0.46 * 12 = $5.52
Hence, the cost of 12 stamps is $5.52
Answer:
Hi there!
Your answer is:
$78
Step-by-step explanation:
To set up this equation:
75+ (.04× 75)
Change 4% into decimal format
75+ ( 3)
78
Hope this helps!
Both the numerator and the denominator can be easily divided by 9. so you get:
2/10
as you can tell it can still be simplified. both the numerator and denominator can be divided by 2. so your final answer is
1/5
A) To find the surface area of a cube, you have to use the formula 6•a^2
meaning you just have to calculate one side and multiply it by six.
541.5 is the surface area of the cube.
B) To find the surface area for just five sides, you'll be doing the same, except instead of 6 it'll be five.
so multiply 9.5 by itself
you get 90.25
Then you multiply 90.5 by 5
You get 451.25
Unfortunately I'm not sure how to do C. good luck