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2 years ago

Solve 9x^2- 17x- 85 = 0 Give your solutions correct to 3 significant figures.

Mathematics

1 answer:

dybincka [34]2 years ago

4 0

Answer:

$x =\frac{17}{18} +\frac{1}{18} \sqrt{3349}$ OR $x =\frac{17}{18} +\frac{-1}{18} \sqrt{3349}$

Step-by-step explanation:

9x2−17x−85=0

For this equation: a=9, b=-17, c=-85

9x2+−17x+−85=0

Step 1: Use quadratic formula with a=9, b=-17, c=-85.

$x =\frac{-b + \sqrt{b^{2}-4ac } }{2a}$

$x =\frac{-(-17)+\sqrt{(-17)^{2} -4(9)(-85)} }{2(9)}$

$x =\frac{17}{18} +\frac{-1}{18} \sqrt{3349}$

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Answer:

Step-by-step explanation:

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Step-by-step explanation:

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3 years ago

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3 years ago

The Resource Conservation and Recovery Act mandates the tracking and disposal of hazardous waste produced at U.S. facilities. Pr

aniked [119]

Answer:

(a) $E(X) = 0.383$

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(b) $P(x = 4) = 0.000169$

There is a 0.000169 probability that 4 of the 10 selected facilities treat hazardous waste on-site.

Step-by-step explanation:

Professional Geographer (Feb. 2000) reported the hazardous waste generation and disposal characteristics of 209 facilities.

N = 209

Only eight of these facilities treated hazardous waste on-site.

r = 8

a. In a random sample of 10 of the 209 facilities, what is the expected number in the sample that treats hazardous waste on-site?

n = 10

The expected number in the sample that treats hazardous waste on-site is given by

$E(X) = \frac{n \times r}{N}$

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$E(X) = 0.383$

Therefore, the expected number in the sample that treats hazardous waste on-site is 0.383.

b. Find the probability that 4 of the 10 selected facilities treat hazardous waste on-site

The probability is given by

$P(x = 4) = \frac{\binom{r}{x} \binom{N - r}{n - x}}{\binom{N}{n}}$

For the given case, we have

N = 209

n = 10

r = 8

x = 4

$P(x = 4) = \frac{\binom{8}{4} \binom{209 - 8}{10 - 4}}{\binom{209}{10}}$

$P(x = 4) = \frac{\binom{8}{4} \binom{201}{6}}{\binom{209}{10}}$

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Therefore, there is a 0.000169 probability that 4 of the 10 selected facilities treat hazardous waste on-site.

8 0

3 years ago

The circumference of a circle can be found using the formula C = 2r. Which is an equivalent equation solved for r? r = C r = C(2

vaieri [72.5K]

Answer:

r equals StartFraction C Over 2 pi EndFraction

Step-by-step explanation:

we know that

The circumference of a circle is equal to

$C=2\pi r$

where

r is the radius of the circle

Solve for r

That means -----> isolate the variable r

Divide by 2π both sides

$\frac{C}{2\pi}=\frac{2\pi r}{2\pi}$

Simplify right side

$\frac{C}{2\pi}=r$

Rewrite

$r=\frac{C}{2\pi}$

r equals StartFraction C Over 2 pi EndFraction

5 0

3 years ago

Read 2 more answers

Solve 9x^2- 17x- 85 = 0 Give your solutions correct to 3 significant figures.​

Solve 9x^2- 17x- 85 = 0 Give your solutions correct to 3 significant figures.