PLEASE HELP IK THIS ISN'T MATH BUT PLEASE HELP ITS TIMED

Select the correct answer.

Dmitry [639]

Answer:

C

Step-by-step explanation:

An undefined slope means that the line is vertical and parallel to the y- axis.

A vertical line has equal x- coordinates of the points it passes through.

The only pair where the x- coordinates are equal are

(- 3, - 3) and (- 3, 3) ← undefined slope → C

6 0

4 years ago

I’m not sure how to do this problem

strojnjashka [21]

The first one would be x^12

6 0

3 years ago

A researcher reports survey results by stating that the standard error of the mean is 25 the population standard deviation is 40

bezimeni [28]

Answer:

a) A sample of 256 was used in this survey.

b) 45.14% probability that the point estimate was within ±15 of the population mean

Step-by-step explanation:

This question is solved using the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore 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 pvalue, 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.

a. How large was the sample used in this survey?

We have that $s = 25, \sigma = 400$ . We want to find n, so:

$s = \frac{\sigma}{\sqrt{n}}$

$25 = \frac{400}{\sqrt{n}}$

$25\sqrt{n} = 400$

$\sqrt{n} = \frac{400}{25}$

$\sqrt{n} = 16$

$(\sqrt{n})^2 = 16^2[tex][tex]n = 256$

A sample of 256 was used in this survey.

b. What is the probability that the point estimate was within ±15 of the population mean?

15 is the bounds with want, 25 is the standard error. So

Z = 15/25 = 0.6 has a pvalue of 0.7257

Z = -15/25 = -0.6 has a pvalue of 0.2743

0.7257 - 0.2743 = 0.4514

45.14% probability that the point estimate was within ±15 of the population mean

3 0

3 years ago

Salem High School's winter sports teams WON 72% of their games last season. If the teams played 50 games, how many games did the

Dmitriy789 [7]

Answer

Find out the how many games did the teams lose .

To prove

Formula

$Percentage = \frac{Part\ value\times 100}{Total\ values}$

As given

Salem High School's winter sports teams WON 72% of their games last season.

If the teams played 50 games .

Percentage = 72%

Total value = 50

Put in the formula

$72 = \frac{Number\ of\ games\ win\times 100}{50}$

$Number\ of\ games\ win = \frac{72\times 50}{100}$

Number of games win = 36

Number of games teams loses = Total number of games - number of games win

= 50 - 36

= 14

Therefore the number of games team loses are 14 .

5 0

3 years ago

HELP!!! Please I need work shown I have no clue how to do this and I need a good answer please and thank you

zheka24 [161]

Factorize x²+7x+12 ===> (x+3)(x+4)

Factorize x²-3x-28 ===> (x-7)(x+4)

4x + 12 can be written====> 4(x+3)

Then the question could be written as follows:

[(x+3)(x+4) / (x-7)(x+4) ] / 4(x+3) = [(x+3)(x+4) / (x-7)(x+4) ].[4(x+30]
After simplification you get 1 / 4(x-7)

7 0

3 years ago