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3 years ago

Marcie solved the following inequality, and her work is shown below:

Mathematics

1 answer:

Cerrena [4.2K]3 years ago

6 0

When dividing an inequality with a negative value , the inequality sign changes direction.

The original Less than or equal to sign should heave been changed to greater than or equal to.

The answer is: When dividing by −8, she did not change the direction of the sign.

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a. Are the following triangles congruent? If so, which postulate or theorem proves this? b. What transformation moved one triang

xenn [34]

Answer:

Yes by SAS

Step-by-step explanation:

If you look at the triangles they have 2 side lenght in common (and since it is a right triange they have all the sides in commmon) and they share an angel

In other words 2 sides are conurent with an angle betwene them.

You would need to rotait the shape 90 degrese.

4 0

2 years ago

The results of a common standardized test used in psychology research is designed so that the population mean is 155 and the sta

galina1969 [7]

Answer:

The value 155 is zero standard deviations from the [population] mean, because $\\ x = \mu$ , and therefore $\\ z = 0$ .

Step-by-step explanation:

The key concept we need to manage here is the z-scores (or standardized values), and we can obtain a z-score using the next formula:

$\\ z = \frac{x - \mu}{\sigma}$ [1]

Where

z is the z-score.
x is the raw score: an observation from the normally distributed data that we want standardize using [1].
$\\ \mu$ is the population mean.
$\\ \sigma$ is the population standard deviation.

Carefully looking at [1], we can interpret it as the distance from the mean of a raw value in standard deviations units. When the z-score is negative indicates that the raw score, x, is below the population mean, $\\ \mu$ . Conversely, a positive z-score is telling us that x is above the population mean. A z-score is also fundamental when determining probabilities using the standard normal distribution.

For example, think about a z-score = 1. In this case, the raw score is, after being standardized using [1], one standard deviation above from the population mean. A z-score = -1 is also one standard deviation from the mean but below it.

These standardized values have always the same probability in the standard normal distribution, and this is the advantage of using it for calculating probabilities for normally distributed data.

A subject earns a score of 155. How many standard deviations from the mean is the value 155?

From the question, we know that:

x = 155.
$\\ \mu = 155$ .
$\\ \sigma = 50$ .

Having into account all the previous information, we can say that the raw score, x = 155, is zero standard deviations units from the mean. The subject earned a score that equals the population mean. Then, using [1]:

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

$\\ z = \frac{155 - 155}{50}$

$\\ z = \frac{0}{50}$

$\\ z = 0$

As we say before, the z-score "tells us" the distance from the population mean, and in this case this value equals zero:

$\\ x = \mu$

Therefore

$\\ z = 0$

So, the value 155 is zero standard deviations from the [population] mean.

5 0

3 years ago

If takes 660 metres of fence to enclose a rectangular field. if one side is 30 metres less that twice the other side, find the d

aliina [53]

Answer:

210 by 120

Step-by-step explanation:

perimeter=2l+2w

length= 2w-30

width= w

2(2w-30+w) = 660

6w-60= 660

6w= 720

w=120

length= 2*120-30 = 210

6 0

3 years ago

Aubree wanted to see if there is a connection between the time a given exam takes place and the average score of this exam. She

Andrews [41]

Answer:

you can divide the answers by the time duration of the exam and get your answer

Step-by-step explanation:

5 0

3 years ago

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I tried to do this but got confused ;0;

mafiozo [28]

Answer:

answer d 242 square feet

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers