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3 years ago

Y=-4. Y=x-8 solve for substitution

Mathematics

2 answers:

Lostsunrise [7]3 years ago

7 0

Answer:

Step-by-step explanation:

I think

Deffense [45]3 years ago

6 0

Point form: (4,-4)
Or x=4, y=-4

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Identify the expression for calculating the mean of a binomial distribution.

Gre4nikov [31]

A random variable $X$ following a binomial distribution with success probability $p$ across $n$ trials has PMF

$\mathbb P(X=x)=\begin{cases}\dbinom nxp^x(1-p)^{n-x}&\text{for }x\in\{0,1,\ldots,n\}\\\\0&\text{otherwise}\end{cases}$

where $\dbinom nx=\dfrac{n!}{x!(n-x)!}$ .

The mean of the distribution is given by the expected value which is defined by

$\mathbb E(X):=\displaystyle\sum_xx\mathbb P(X=x)$

where the summation is carried out over the support of $X$ . So the mean is

$\displaystyle\sum_{x=0}^nx\binom nxp^x(1-p)^{n-x}$

Because this is a proper distribution, you have

$\displaystyle\sum_x\mathbb P(X=x)=1$

which is a fact that will be used to evaluate the sum above.

$\displaystyle\sum_{x=0}^nx\binom nxp^x(1-p)^{n-x}$
$\displaystyle\sum_{x=1}^nx\binom nxp^x(1-p)^{n-x}$
$\displaystyle\sum_{x=1}^n\frac{xn!}{x!(n-x)!}p^x(1-p)^{n-x}$
$\displaystyle np\sum_{x=1}^n\frac{(n-1)!}{(x-1)!(n-x)!}p^{x-1}(1-p)^{n-x}$
$\displaystyle np\sum_{x=1}^n\frac{(n-1)!}{(x-1)!((n-1)-(x-1))!}p^{x-1}(1-p)^{(n-1)-(x-1)}$

Letting $y=x-1$ , this becomes

$\displaystyle np\sum_{y=0}^{n-1}\frac{(n-1)!}{y!((n-1)-y)!}p^y(1-p)^{(n-1)-y}$

Observe that the remaining sum corresponds to the PMF of a new random variable $Y$ which also follows a binomial distribution with success probability $p$ , but this time across $n-1$ trials. Therefore the sum evaluates to 1, and you're left with $np$ as the expression for the mean for $X$ .

3 0

4 years ago

1/2z +5=11 how to solve it plese??!

solong [7]

$\frac{z}{2} + 5 = 11 \ / \ simplify \\ \\ \frac{z}{2} = 11 - 5 \ / \ subtract \ 5 \ from \ each \ side \\ \\ \frac{z}{2} = 6 \ / \ simplify \\ \\ x = 6 \times 2 \ / \ multiply \ each \ side \ by \ 2 \\ \\ z = 12 \ / \ simplify \\ \\$

So, your answer to this problem is z = 12.

5 0

3 years ago

Read 2 more answers

Which of the following parametric equations are equivalent to the polar equation r=3 cos theta

Allushta [10]

To solve the problem you must know that to change from Cartesian to polar coordinates you must write:
x = rcos (θ)
Where "r" is the radius
Likewise y = rsin (θ)
Therefore, in the expression r = 3cos (θ) one can write r as:
r = x / cos (θ)
So:
x / cos (θ) = 3cos (θ)
x = 3cos ^ 2 (θ)
The same for y ...
y = rsin (θ)
y = 3cos (θ) sin (θ).

Finally the correct answer is option 2.
x = 3cos ^ 2 (θ) y = 3cos (θ) sin (θ).

5 0

3 years ago

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Ella is going to drive from her house to city a without stopping. Ella’s house is 100 miles from city a and after driving three

aleksley [76]

Answer:
d = 100 - 25t

Step-by-step explanation:

Let's use basic logic here.
If we are 100 miles away from a place, and we've got 25 miles to go, we've already travelled 75 miles.
Since we've travelled 75 miles in 3 hours, then we travel at a rate of 75 divided by 3 = 25 miles per hour.

The distance to City A will be represented as 100 - miles already travelled. We can find how many miles have been travelled by multiplying 25 by t, the amount of hours we've spent driving.

This creates the equation d = 100 - 25t
Hope this helped!

8 0

3 years ago

Two Pairs Of Jeans Cost $75 before tax. If the total paid for the two pairs of jeans with tax was $81, what is the percentage of

Elden [556K]

Answer:

31%

Step-by-step explanation:

100- 75 = 25

25/81 = 0.308 = 31%

6 0

4 years ago

Read 2 more answers