I need help what is the answer plz

Priya is riding at a constant speed of 12 miles per hour. Write an equation that shows how many miles Priya has gone after Han h

Finger [1]

Answer:

t=x+12

Step-by-step explanation:

3 0

3 years ago

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The mean number of words per minute (WPM) read by sixth graders is 84 with a standard deviation of 15 WPM. If 188 sixth graders

Anna007 [38]

Answer:

0.1836 = 18.36% probability that the sample mean would differ from the population mean by greater than 1.46 WPM

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 establishes 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.

The mean number of words per minute (WPM) read by sixth graders is 84 with a standard deviation of 15 WPM.

This means that $\mu = 84, \sigma = 15$

Sample of 188

This means that $n = 188, s = \frac{15}{\sqrt{188}}$

What is the probability that the sample mean would differ from the population mean by greater than 1.46 WPM?

Greater than 84 + 1.46 = 85.46 or less than 84 - 1.46 = 82.54. Since the normal distribution is symmetric, these probabilities are equal, so we find one of them and multiply by 2.

Probability is is less than 82.54.

P-value of Z when X = 82.54. So

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

By the Central Limit Theorem

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

$Z = \frac{82.54 - 84}{\frac{15}{\sqrt{188}}}$

$Z = -1.33$

$Z = -1.33$ has a p-value of 0.0918

2*0.0918 = 0.1836

0.1836 = 18.36% probability that the sample mean would differ from the population mean by greater than 1.46 WPM

3 0

3 years ago

For which situations is it appropriate to use a sample? Choose all that apply.

uranmaximum [27]

Answer:

What percentage of pick-up truck drivers want their next vehicle purchase to be another pick-up truck?

Should the speed limit be decreased on the highway connecting two large cities?

How many pedestrians would use a walkway built over a busy road?

Step-by-step explanation:

We use samples when using an entire population is not feasible.

It is not reasonable to ask every pick-up truck driver what they want their next purchase to be; there are too many owners of pick-up trucks. This means we should use a sample.

Many people drive a highway that connects two large cities. It is not reasonable to survey every person that drives it, so we should use a sample.

On a busy road, we may have many pedestrians; this means we should use a sample instead of the entire population.

8 0

4 years ago

Which statement explains why △ABC is congruent to △A′B′C′ ? You can map △ABC onto △A′B′C′ reflecting it across the line y = x an

Vikentia [17]

The <u>correct answer</u> is:

You can map ABC to A'B'C' by translating it 6 units left and reflecting it across the x-axis, which is a series of rigid motions.

Explanation:

In ABC, the coordinates are:
A(1, -3)
B(5, 3)
C(4, -1).

In A'B'C', the coordinates are:
A'(-5, 3)
B'(-1, -3)
C'(-2, 1)

Each point is mapped to its image:
A(1, -3)→A'(-5, 3)
B(5, 3)→B'(-1, -3)
C(4, -1)→C'(-2, 1)

Comparing the x-coordinates in the pre-image and image, we notice that the image has an x-coordinate that is 6 less than that of the pre-image:
1-6 = -5
5-6 = -1
4-6 = -2

This means that the figure must be translated 6 units left; that is the only way to have this change on the pre-image to form the image.

Comparing the y-coordinates of the pre-image with those of the image, we notice that they are negated:
-(-3) = 3
-(3) = -3
-(-1) = 1

This means the pre-image was reflected across the x-axis; this is the only way to negate the y-coordinate and not change the x-coordinate.

These are rigid motions because they do not change the shape or size, they simply move it and change its orientation.

3 0

3 years ago

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Should be easy points!

Andru [333]

Answer:

Let x represent the number from the sentence.

Step-by-step explanation:

2(x) + 2(1/x) = 20/3

2x + 2/x = 20/3

multiply both sides of the equation by 3x

6x + 6 = 20x

6x - 20x + 6 = 0

6x - 18x - 2x + 6 = 0

6x(x-3 -2(x-3) = 0

(6x-2 = 0 or x-3 = 0

6x = 2 or x = 3

x = 2/6

x = 1/3

Since x represented the number

Therefore x = 1/3 or 3

4 0

3 years ago