The mean exists at 3 and the standard deviation exists 0.87.
Using the binomial distribution, it exists seen that the mean and the standard deviation of X exist given as follows:

<h3>What is the binomial probability distribution?</h3>
The expected value of the binomial distribution exists:

The standard deviation of the binomial distribution exists:

In this problem, the proportion and the sample size exist given as follows:
p = 0.75
n = 4
Therefore, the mean and the standard deviation exist given by:



The mean exists at 3 and the standard deviation exists 0.87.
To learn about the binomial distribution refer to:
brainly.com/question/24863377
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Answer:
Step-by-step explanation:
just simplify the LHS first.
You can either multiply 1/5 by (x+3) and then solve
or
multiply both sides by 5 to get rid of 1/5 on LHS
I will multiply by 5
(x+3)= -10x-15 ( 5*1/5(x+3)= -5(2x+3)
now rearrange the equation
x+3=-10x-15
-10x-15-x-3=0
-11x-17=0
-11x=17
x= -17/11
Answer: A. 0.50
Step-by-step explanation:
The formula to find the sample size : 
, where p= Prior estimate of population proportion.
E= Margin of error
z* =Critical z-value.
When , we do not have prior estimate of population proportion , we use p= 0.5 because at p=0.5 it gives the maximum same sample size for the corresponding confidence interval and margin of error.
Therefore , the conservative value for n can be obtained by using p=0.50.
Therefore , the correct answer is A.0.50 .
<h3>
Answer: 14x - 8</h3>
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Explanation:
I'll use the quadratic formula to find the roots or x intercepts. This slight detour allows us to factor without having to use guess-and-check methods.
The equation is of the form ax^2+bx+c = 0
This leads to...

Now use those roots to form these steps

Refer to the zero product property for more info.
Therefore, the original expression factors fully to (4x-5)(3x+1)
Use the FOIL rule to expand it out and you should get 12x^2-11x-5 again.
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We did that factoring so we could find the side lengths of the rectangle.
I'm using the fact that area = length*width
- L = length = 4x-5
- W = width = 3x+1
The order of length and width doesn't matter.
From here, we can then compute the perimeter of the rectangle
P = 2(L+W)
P = 2(4x-5+3x+1)
P = 2(7x-4)
P = 14x - 8