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3 years ago

What’s the answer to this ?

Mathematics

1 answer:

tiny-mole [99]3 years ago

8 0

Answer:

see below for a plot
9

Step-by-step explanation:

If you properly plot the points, you can count the grid squares to see how long the line is between the points. (The line is just to show the measurement you're making. It is not required by the problem.)

As you know, an (x, y) coordinate pair refers to the point that is x units to the right of the y-axis and y units above the x-axis. A negative x value sends you in the left direction, and a negative y-value is below the x-axis, rather than above. On your grid, you can count the squares to locate the points.

There are 9 units between -3 and +6. That's the distance between the endpoints on the horizontal line.

You might be interested in

Find value of variable

Nezavi [6.7K]

Step 1: Identify the variables.
Step 2: Add/Subtract whole numbers so they're all on one side.
Step 3: Add/Subtract Variables so they're all on one side.
Step 4: Multiply /Divide to get the variable by itself.
Step 5: Check your work.

4 0

3 years ago

Why are convenience samples are not desirable?

Igoryamba

Answer:

The disadvantages: Convenience samples do not produce representative results. If you need to extrapolate to the target population, convenience samples aren't going to get you there. ... Much larger convenience samples are not more accurate than small probability samples.

8 0

2 years ago

Alguien me pude decir una adivinanza o historia q la solución sea una ecuación de segundo grado completa????

Hitman42 [59]

Answer:

Una ecuación de segundo grado completa es algo como:

y = a*x^2 + b*x + c

Un problema tipico que usa ecuaciones de este tipo es algo que nos haga multiplicar dos términos como h*(x + k) y n*(x + j)

Donde h, k, n, y j son números reales.

Entonces planteemos el siguiente caso.

"Juan tiene una tabla rectangular, de tal forma que su largo es (x + 3cm), y el ancho es igual a dos veces su largo, si sabemos que el área de esta tabla es 95 cm^2 ¿cuál es el valor de x?"

Acá hay que recordar que para un rectángulo de largo L y ancho W, el área es:

A = L*W

En este caso tendremos:

L = (x + 3cm)

Y el ancho es dos veces eso, entonces:

W = 2*(x + 3cm)

Entonces el area de esta tabla se escribirá como:

A = (x + 3cm)*2*(x + 3cm)

Ahora solo tenemos que expandir eso:

A = 2*x^2 + 12cm*x + 18cm^2

Ahora sabemos que el area de esta tabla es 95cm^2

Entonces:

95cm^2 = 2*x^2 + 12cm*x + 18cm^2

0 = 2*x^2 + 12cm*x + (18cm^2 - 95cm^2)

0 = 2*x^2 + 12cm*x - 77 cm^2

Esta es una ecuación de segundo grado completa, la cual deberiamos resolver para encontrar el valor de x como se nos pide en el problema.

4 0

2 years ago

From 19 measurements of a pressure controller, the mean operating pressure is 4.97 kPa with a standard deviation of 0.0461 kPa.

Semenov [28]

Answer:

$4.97-2.10\frac{0.0461}{\sqrt{19}}=4.95$

$4.97+2.10\frac{0.0461}{\sqrt{19}}=4.99$

So on this case the 95% confidence interval would be given by (4.95;4.99)

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

$\bar X =4.97$ represent the sample mean

$\mu$ population mean (variable of interest)

s=0.0461 represent the sample standard deviation

n=19 represent the sample size

Confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=19-1=18$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,18)".And we see that $t_{\alpha/2}=2.10$