What is the difference between 76.82 and 2.761? 49.210 74.679 74.059 79.581

The diagram shows a circle inside a square. a O 16 cm Work out the area of the circle.

LuckyWell [14K]

Answer:

perimeter of circle=2πr

16=2πr

r=16/2π=8/πcm

now.

area of circle=πr²=π(8/π)²=π×64/π²=64/(22/7)=64×7/22=20.36cm²

4 0

2 years ago

Does anyone know this?

Bumek [7]

Answer:

B

Step-by-step explanation:

Initial mean = 156, Changed mean = 163.92

So, mean increases. Only condition that satisfies this is B.

7 0

3 years ago

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

PLEASE HELP ASAP WILL GIVE BRAINLEST

Fittoniya [83]

Each ratio is
3:1
3:1
3:1
3:1

7 0

3 years ago

Solve each equation. 3) 4= 2x + 3.x

Andrej [43]

Answer:

Step-by-step explanation:

2x+3x=4

5x=4

x=4/5

6 0

2 years ago

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