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3 years ago

6

Can someone explain to me why this is right?

1 answer:

Flauer [41]3 years ago

3 0

Hello!

This is right because the goal of solving a quadratic equation is to isolate the variable and then solve it. First you multiply - 8/3 to both sides to isolate s and the you solve the equation by multiplying - 8/3 to - 6

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Question In Picture, Thanks.

Ainat [17]

6z to the 4th power - 2z to the 3rd power

5 0

3 years ago

The probability density function of the time to failure of an electronic component in a copier (in hours) is f(x) for Determine

salantis [7]

The question is incomplete. Here is the complete question.

The probability density function of the time to failure of an electronic component in a copier (in hours) is

$f(x)=\frac{e^{\frac{-x}{1000} }}{1000}$

for x > 0. Determine the probability that

a. A component lasts more than 3000 hours before failure.

b. A componenet fails in the interval from 1000 to 2000 hours.

c. A component fails before 1000 hours.

d. Determine the number of hours at which 10% of all components have failed.

Answer: a. P(x>3000) = 0.5

b. P(1000<x<2000) = 0.2325

c. P(x<1000) = 0.6321

d. 105.4 hours

Step-by-step explanation: <em>Probability Density Function</em> is a function defining the probability of an outcome for a discrete random variable and is mathematically defined as the derivative of the distribution function.

So, probability function is given by:

P(a<x<b) = $\int\limits^b_a {P(x)} \, dx$

Then, for the electronic component, probability will be:

P(a<x<b) = $\int\limits^b_a {\frac{e^{\frac{-x}{1000} }}{1000} } \, dx$

P(a<x<b) = $\frac{1000}{1000}.e^{\frac{-x}{1000} }$

P(a<x<b) = $e^{\frac{-b}{1000} }-e^\frac{-a}{1000}$

a. For a component to last more than 3000 hours:

P(3000<x<∞) = $e^{\frac{-3000}{1000} }-e^\frac{-a}{1000}$

Exponential equation to the infinity tends to zero, so:

P(3000<x<∞) = $e^{-3}$

P(3000<x<∞) = 0.05

There is a probability of 5% of a component to last more than 3000 hours.

b. Probability between 1000 and 2000 hours:

P(1000<x<2000) = $e^{\frac{-2000}{1000} }-e^\frac{-1000}{1000}$

P(1000<x<2000) = $e^{-2}-e^{-1}$

P(1000<x<2000) = 0.2325

There is a probability of 23.25% of failure in that interval.

c. Probability of failing between 0 and 1000 hours:

P(0<x<1000) = $e^{\frac{-1000}{1000} }-e^\frac{-0}{1000}$

P(0<x<1000) = $e^{-1}-1$

P(0<x<1000) = 0.6321

There is a probability of 63.21% of failing before 1000 hours.

d. P(x) = $e^{\frac{-b}{1000} }-e^\frac{-a}{1000}$

0.1 = $1-e^\frac{-x}{1000}$

$-e^{\frac{-x}{1000} }=-0.9$

${\frac{-x}{1000} }=ln0.9$

-x = -1000.ln(0.9)

x = 105.4

10% of the components will have failed at 105.4 hours.

5 0

4 years ago

Suppose the goal for mr. Luockwoods class had been 250 cans. Then 550 cans would have been what percent of the goal?

ser-zykov [4K]

220% of the goal. This is because 500 cans would be 200% but since it’s 550, the extra 50% would equal to 220%.

3 0

3 years ago

4 quarters are equal in value to 20 nickels.

Brums [2.3K]

Answer:

30

70

5 (5 nickels for every 1 quarter)

4 0

3 years ago

Find the value of x and y

tankabanditka [31]

Answer:

x = 3, y = 10.

Step-by-step explanation:

The 2 triangles are similar so the corresponding sides are in the same ratio.

x/6 = 4/8

x/6 = 1/2

x = 6/2 = 3.

y/5 = 8/4 = 2

y = 5*2 = 10,

8 0

3 years ago

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