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2 years ago

Plz help :)))))))))))))))))))))))))

Mathematics

1 answer:

solong [7]2 years ago

5 0

Answer:im in 9th so im going to say 3)30/y\80

Step-by-step explanation:

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In a recent year, Washington State public school students taking a mathematics assessment test had a mean score of 276.1 and a s

Oksi-84 [34.3K]

Answer:

a) $\mu_{\bar x} =\mu = 276.1$

$\sigma_{\bar x} =\frac{\sigma}{\sqrt{n}}=\frac{34.4}{\sqrt{64}}=4.3$

b) From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu=276.1, \frac{\sigma}{\sqrt{n}}=4.3)$

c) $P(\bar X \geq 285)=P(Z\geq \frac{285-276.1}{4.3}=2.070)$

$P(Z\geq2.070)=1-P(Z$

Step-by-step explanation:

Let X the random variable the represent the scores for the test analyzed. We know that:

$\mu=E(X) = 276.1 , \sigma=Sd(X) = 34.4$

And we select a sample size of 64.

The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

Part a

For this case the mean and standard error for the sample mean would be given by:

$\mu_{\bar x} =\mu = 276.1$

$\sigma_{\bar x} =\frac{\sigma}{\sqrt{n}}=\frac{34.4}{\sqrt{64}}=4.3$

Part b

From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu=276.1, \frac{\sigma}{\sqrt{n}}=4.3)$

Part c

For this case we want this probability:

$P(\bar X \geq 285)$

And we can use the z score defined as:

$z=\frac{\bar x -\mu}{\sigma_{\bar x}}$

And using this we got:

$P(\bar X \geq 285)=P(Z\geq \frac{285-276.1}{4.3}=2.070)$

And using a calculator, excel or the normal standard table we have that:

$P(Z\geq2.070)=1-P(Z$

8 0

3 years ago

In the XY coordinate plane, the slope of a line is 4 and it passes through the point (1,3). Find the equation of a line that is

Sergeeva-Olga [200]

Answer:

Step-by-step explanation:

I'm sorry of this answer is wrong

7 0

2 years ago

In the parallelogram below,<br> x = [? ]°<br> Z<br> 339<br> 1249

diamong [38]

Answer:

Step-by-step explanation:

Angle x and the two given angles form a triangle. The interior angles of a triangle add up to be 180.

$124 + 33 + x = 180$

$157 + x = 180$

$x = 23$

8 0

2 years ago

Write the ratio for sin P and cos Q

Gnom [1K]

Answer:

sin p -21/29

cos q 21/29 so here you go °~sohcahtoa~°

Step-by-step explanation:

sin means you find the soh part so you look for the oppisite over hyponuse

and for cos your looking for cah part so you find the adjsent over hypotnuse so the ansers is 21/29

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2 years ago

Sarah bought a sweater at the sale price of $18 the original cost of the sweater was $40 what percent represents the discount th

igomit [66]

Let’s remember the most basic thing in percentages, the equation.

Percent x Whole = Part.

We know the whole, and the part, but we are trying to find the percent, so we have to divide the two, first turn your whole and part into a decimal.

Percent x 0.4 = 0.18, so we divide 0.18 by 0.4

0.18/0.4 = 0.45

0.45 = 45%

8 0

2 years ago