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4 years ago

I need help please and thank you

Mathematics

1 answer:

Phoenix [80]4 years ago

8 0

Answer:

28.26

Step-by-step explanation:

This is the formula for area of a circle

A = pi r^2

Substitute the given values

A = 3.14 (3)^2

A = 3.14 (9)

28.26

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Dairy cows at large commercial farms often receive

IrinaK [193]

Answer:

a) The 99% confidence interval for the true mean milk production is (26.35 kg/d, 29.65 kg/d).

b) They would need to use a confidence level of 94.52%.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.99}{2} = 0.005$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

Now, find M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample. So

$M = 2.575*\frac{2.25}{\sqrt{12}} = 1.65$

The lower end of the interval is the mean subtracted by M. So it is 28-1.65 = 26.35 kg/d

The upper end of the interval is the mean added to M. So it is 28 + 1.65 = 29.65 kg/d.

The 99% confidence interval for the true mean milk production is (26.35 kg/d, 29.65 kg/d).

(b) If the farms want the confidence interval to be no wider than 1.25 kg/d, what level of confidence would they need to use?

Now we want to find the value of z when M = 1.25. So:

$1.25 = z*\frac{2.25}{\sqrt{12}}$

$0.6495z = 1.25$

$z = 1.92$ , that has a pvalue of 0.9726.

So the confidence level should be 1 - 2*(1-0.9726) = 0.9452

They would need to use a confidence level of 94.52%.

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3 years ago

What does it mean to say that a data point has a residual of 0

Elina [12.6K]

<span>It means that the point lies directly on the regression line.
</span>

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4 years ago

A 26-foot long ladder is leaning against a building at a 60 degree angle with the ground.

Anvisha [2.4K]

A.

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8 0

3 years ago

Read 2 more answers

If u(x) = x^2 – x^4 + x^2 and v(x) = –x2, which expression is equivalent to (u/v)(x)?

bazaltina [42]

(u/v)(x) =

x^2 - x^4 + x^2

---------------------- = - (1 - x^2 + 1) = - (2 - x^2).

-x^2

I'd suggest you double check to ensure that you've copied down this problem correctly.

4 0

3 years ago

If 2/3 = x/y, then which of the following must be true?

Kazeer [188]

Correct option is third $\frac{2+3}{3}=\frac{x+y}{y}$

<h3><u>Solution:</u></h3>

Given that:

$\frac{2}{3}=\frac{x}{y}$

Need to check which of the expression from given four expressions will be true.

Let's first try to eliminate wrong options.

If we observe carefully, we can say that option 2 that is $\frac{3}{2}=\frac{x}{y}$ is not correct as $\frac{x}{y}$ must be equal to $\frac{2}{3}$ and not $\frac{3}{2}$

Lets now modify given expression that is:

$\frac{2}{3}=\frac{x}{y}$

On adding 1 to both sides we get

$\frac{2}{3}+1=\frac{x}{y}+1$

$=>\frac{2+3}{3}=\frac{x+y}{y} \text { which is same as third option. }$

Hence correct option is third one that is $\frac{2+3}{3}=\frac{x+y}{y}$

6 0

3 years ago