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3 years ago

A building engineer analyzes a concrete column with a circular cross section. The circumference of the column is 18π meters.

Mathematics

1 answer:

Whitepunk [10]3 years ago

8 0

Answer:

$A=81\pi\ m^{2}$

Step-by-step explanation:

Step 1

Find the radius of the circular cross section

we know that

The circumference is equal to

$C=2\pi r$

we have

$C=18\pi\ m$

substitute and solve for r

$18\pi=2\pi r$

simplify

$18=2 r$

$r=9\ m$

Step 2

Find the area of the circular cross section

The area of the circle is equal to

$A=\pi r^{2}$

we have

$r=9\ m$

substitute

$A=\pi (9)^{2}$

$A=81\pi\ m^{2}$

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200x - y + 500= 0 Put it in Y=mx + b form

blondinia [14]

Answer:

Step-by-step explanation:

1. Put y on the other side - 200x + 500 = y

y= 200x +500

See, this works because -y, when bringing it to another side, you would be adding it. That cancels out the negative, giving you your slope-intercept form. All you have to do is flip it into y=mx + b form, and that's how you get y=200x + 500

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2 years ago

The national mean sales price for a new one-family home is $181,900. A sample of 40 one-family homes in the south showed a sampl

SIZIF [17.4K]

Answer:

The null hypothesis is $\mu = \$181,900$

The alternative hypothesis is $\mu < \$ 181.900$

$t = -2.92$

$p-value = 0.0016948$

There no sufficient evidence to support the conclusion that the population mean sales prices for new one-family homes in the South is less expensive than the national mean of $181,900

Step-by-step explanation:

From the question we are told that

The population mean is $\mu = \$ 181, 900$

The sample size is $n = 40$

The sample mean is $\= x = \$ 166,400$

The sample standard deviation is $s= \$ 33, 500$

The null hypothesis is $\mu = \$181,900$

The alternative hypothesis is $\mu < \$ 181.900$

Generally the test statistics is mathematically represented as

$t = \frac{ \= x - \mu }{ \frac{s}{\sqrt{n} } }$

=> $t = \frac{ 166400 - 181900 }{ \frac{33500}{\sqrt{40} } }$

=> $t = -2.92$

Generally the p-value is obtain from the z-table the value is

$p-value = P(Z < t ) = P(Z < -2.93) = 0.0016948$

=> $p-value = 0.0016948$

From the calculation we see that

$p-value > \alpha$ hence we fail to reject the null hypothesis

Thus there no sufficient evidence to support the conclusion that the population mean sales prices for new one-family homes in the South is less expensive than the national mean of $181,900

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3 years ago

The zeros of a parabola are –4 and 2, and (6, 10) is a point on the graph. Which equation can be solved to determine the value o

Oliga [24]

The equation of the parabola is
.. y = a(x +4)(x -2)

Substituting (x, y) = (6, 10) gives
.. 10 = a(6 +4)(6 -2)

The 4th selection is appropriate.

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3 years ago

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What is 5/8 as a decimal please give explanation WILL GIVE CROWN

liq [111]

Answer:

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