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Certain answers please, I raised it ;)

Certain answers please, I raised it ;)-example-1
User Wicket
by
6.0k points

2 Answers

5 votes

Answer:

Hello!!! Princess Sakura here ^^

Explanation:

a) p=1/2

b) 25

User Chandra Sekar
by
6.1k points
3 votes

Answer:

1) p=1/2

2) V(p)=25

Explanation:

We have the function:


V(p)=100p(1-p)

Which represents the variance of the number of left handed people in a group of 100.

Question 1)

We want to find the value of p that maximizes the variance.

Let's examine our function. We can see that it is a quadratic. Therefore, the value of p that maximizes the variance will simply be the x-coordinate of the vertex of our equation.

Let's expand our function:


V(p)=100p(1-p)

Distribute:


V(p)=100p-100p^2

Let's find the vertex of our equation. We can use the following formulas (I switched out the x for p):


p=-b/2a,\ V(-b/2a)

Let's determine our coefficients. The "a" is the coefficient in front of the squared term and "b" is the coefficient in front of the x term.

So, a is -100, and b is 100.

Substitute them into our formula:


p=-(100)/2(-100)

Multiply:


p=100/200

Divide:


p=1/2

So, the x-coordinate (or rather p in this case) of our vertex is 1/2.

To find the y-value, let's substitute it back into our function. We have:


V(p)=100p-100p^2

Substitute 1/2 for p:


V(1/2)=100(1/2)-100(1/2)^2

Evaluate:


V(1/2)=50-25=25

Therefore, our vertex is:


(1/2, 25)

So, the value of p that maximizes our variance is p=1/2.

Question 2)

We want to find the maximum variance.

Again, this will simply be the vertex of our quadratic.

This time, it will be the y-coordinate.

We can see that the y-coordinate of the vertex is 25.

So, our maximum variance is V(p)=25.

And we're done!

User MarcH
by
5.9k points