Answer:

And the best option would be:

Step-by-step explanation:
We assume that the distribution for the random variable is:

For this case we want to calculate the following probability:

And we can use the normal standard distribution or excel and we got:

And the best option would be:

Answer:
fourth number is 9
Step-by-step explanation:
let 'x' equal the fourth number
(5+7+7+x)/4 = 7
cross-multiply to get:
19 + x = 28
x = 9
I bet you're doing the Law of Sines right now. If you use the law of sines you find out that angle A is a 90 degree angle. There is only one triangle you can make with these measurements because if you have one angle of 30 and another of 90, the 3rd angle has to be a 60 degree angle. So it is a special right triangle, 30-60-90
The answer is Radical 6.
This is because if you use Cosine and the angle measured 30. You would put adjacent over hypotenuse, which is
Cos (30) = X/radical 8
Put this into your calculator to get Radical 6