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3 years ago

Solve -2(5x – 3) = 41.

Mathematics

2 answers:

PSYCHO15rus [73]3 years ago

7 0

Answer:

Divide both sides by the numeric factor on the left side, then solve.

Exact Form:

x=−7/2

Decimal Form:

x=−3.5

Mixed Number Form:

x=−3 1/2

Step-by-step explanation:

liberstina [14]3 years ago

5 0

Answer:

- 3.5

Step-by-step explanation:

hope this helps :)

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Need help!! what is the ewuation of the like shown?

Marta_Voda [28]

Answer:

An equation is y = 2x + 4.

Step-by-step explanation:

ANOTHER equation is y - 2 = 2(x + 1)

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3 years ago

Twice a number, added to seven, is the same

eduard

Answer:

Your number is -10

Hope this helps :)

Step-by-step explanation:

Let x be the number

Twice a number is 2x

Added to 7 means + 7 so 2x + 7

Is means =

2x+7=

At this point I have to assume you mean

"is the same as three subtracted from THE SAME number"

Otherwise, rather than a number, we end up with the

equation of a line....

2x + 7 = x - 3 subtract x from both sides

x + 7 = -3 subtract 7 from both sides

x = -10

Your number is -10

Check: 2x+7 = x-3

2(-10) + 7 = -10-3

-20+7 = -13

-13 = -13

The answer fits the parameters of the problem.

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3 years ago

Carol is painting a four square game court on a school playground. The four small squares are all the same size. If the total ar

Sliva [168]

Given that the total area of the four small squares is 256 ft2, the first thing we are going to do is to divide 256 by 4 and we get 64. So the area of each small square is 64. Now, to find the side length of each small square, we just have to square 64, and the answer is 8. Therefore, the side length of each small square is 8feet. Hope this helps.

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3 years ago

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Please Help me! Choose an answer Thanks

earnstyle [38]

Answer:

Step-by-step explanation:

The change rate is just to big to differ from 2-4 and M isnt the same rate as P in the problem, so the answer would be C. (hoped this helped :D

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3 years ago

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Scores at a local high school on the American College Testing (ACT) college entrance exam follow the normal distribution with a

san4es73 [151]

Answer:

a) The mean is 18 and the standard deviation is 1.79.

b) The interpretation is that the standard deviation of the sample means of groups of 20 students will be of 1.79, which is the sample error, which is different from the population standard deviation.

c) 0.2005 = 20.05% probability that a sample of 20 students has a mean score of 19.5 or more.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 18 and a standard deviation of 8.

This means that $\mu = 18, \sigma = 8$

Sample of 20:

This means that $n = 20, s = \frac{8}{\sqrt{20}} = 1.79$

(a) Calculate the mean and standard deviation of the sampling distribution of x¯.

By the Central Limit Theorem, the mean is 18 and the standard deviation is 1.79.

(b) Interpret the standard deviation from part (a).

The interpretation is that the standard deviation of the sample means of groups of 20 students will be of 1.79, which is the sample error, which is different from the population standard deviation.

(c) Find the probability that a sample of 20 students has a mean score of 19.5 or more.

This is 1 subtracted by the pvalue of Z when X = 19.5. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$