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3 years ago

How do you write the equation of a line (in slope intercept form) with three given points?

2 answers:

6 0

You only need two points to write the equation of a line.

Slope intercept form of a line is y=mx+b, where m is the slope and b is the y intercept.

I’m going to use the points (5,3) and (8,5) to show how to write the equation.

First, find the slope. The formula to find the slope is y2-y1/x2-x1. With my points, the slope equation would look like this:
m=(5-3)/(8-5)
m=2/3

I put this into my point slope formula
y=2/3x+b

To find out the b (y-intercept), I plug in one pair of points, then solve for b. I will use (5,3)

3=2/3(5)+b
3=10/3+b
-1/3=b

I can now add b to my equation, and get y=2/3x-1/3

To double check this, I could graph this line and make sure that it crosses my selected points. Hope this helps!

Mrrafil [7]3 years ago

3 0

With even just two points, you can find the equation of a line in slope-intercept form.

Slope-intercept form: $y=mx+b$ where $m$ is the slope and $b$ is the y-intercept

1) Solve for the slope ( $m$ )

The equation to solve for the slope is $m=\frac{y_2-y_1}{x_2-x_1}$ when the two points are $(x_1,y_1)$ and $(x_2,y_2)$ . Plug the coordinates of these points into the equation and solve for $m$ .

Then, plug $m$ into $y=mx+b$ .

1) Solve for the y-intercept ( $b$ )

Then, take any of the given points and plug it into $y=mx+b$ along with the slope. Isolate $b$ to get the y-intercept. Then, plug both m and b back into $y=mx+b$ to get your final equation.

I hope this helps!

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Wires manufactured for use in a computer system are specified to have resistances between 0.11 and 0.13 ohms. The actual measure

Marina CMI [18]

Answer:

a) $P(0.11$

And we can find this probability with this difference and with the normal standard table or excel:

$P(-1.11$

b) $P(0.11 < \bar X < 0.13)$

And we can use the z score defined by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And using the limits we got:

$z = \frac{0.11-0.12}{\frac{0.009}{\sqrt{4}}}= -2.22$

$z = \frac{0.13-0.12}{\frac{0.009}{\sqrt{4}}}= 2.22$

And we want to find this probability:

$P(-2.22< Z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Part a

Let X the random variable that represent the resitances of a population, and for this case we know the distribution for X is given by:

$X \sim N(0.12,0.009)$

Where $\mu=0.12$ and $\sigma=0.009$

We are interested on this probability

$P(0.11$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(0.11$

And we can find this probability with this difference and with the normal standard table or excel:

$P(-1.11$

Part b

We select a sample size of n =4. And since the distribution for X is normal then we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And we want this probability:

$P(0.11 < \bar X < 0.13)$

And we can use the z score defined by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And using the limits we got:

$z = \frac{0.11-0.12}{\frac{0.009}{\sqrt{4}}}= -2.22$

$z = \frac{0.13-0.12}{\frac{0.009}{\sqrt{4}}}= 2.22$

And we want to find this probability:

$P(-2.22< Z$

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3 years ago

Read 2 more answers

A store is having a sale where winter clothes are 60% of the original price. A sweater is on sale for $30 . What was the origina

Flura [38]

$x-price\ before\ sale\\60\%=0.6\\100\%=1\\\\From\ proportion:\\\\0.6\ \ \ \ \ -\ \ \ \ 30\\1\ \ \ \ \ \ \ \ -\ \ \ \ x\\\\0.6x=30\ \ |:0.6\\x=50\\\\Original\ price\ was\ \$50.$

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3 years ago

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Complete the square to make a perfect square trinomial. Then, write the result as a binomial squared. n^2-4n/3

ololo11 [35]

Answer:

(n- 2/3)²

Step-by-step explanation:

Perfect square trinomial is: a²+2ab+b²= (a+b)²

We have:

n² - 4n/3

It can be put as:

n² -2×n×2/3

Here we consider n = a and -2/3 = b, then

b²= (-2/3)²= 4/9

Now we add 4/9 to a given binomial to make it perfect square:

n² - 2×n×3/2 + 4/9= (n- 2/3)²

So, added 4/9 and got a perfect square (n- 2/3)²

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4 years ago

What’s the distance formula

Whitepunk [10]

Step-by-step explanation:

$\text{Let}\ A(x_1,\ y_1)\ \text{and}\ B(x_2,\ y_2).\ \text{Then the distance between}\ A\ \text{and}\ B\ \text{is:}\\\\|AB|=\sqrt{(x_2-x_1)^2+(y_2-y1)^2}\\\\Example:\\\\A(2,\ 5),\ B(-1,\ 1)\\\\|AB|=\sqrt{(-1-2)^2+(1-5)^2}=\sqrt{(-3)^2+(-4)^2}=\sqrt{9+16}=\sqrt{25}=5$