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3 years ago

Consider two events such that P(A) = 1/4 , P(B) = 2/3 , and P(A ∩ B) = 1/5 . Are events A and B independent events?

1 answer:

4 0

P(A) = 1/4
p(B) = 2/3
p(A ∩ B) = 1/5
p(A).p(B) = 2/12 = 1/6 ≠p(A ∩ B )
thus no, they are dependent because P(A) ⋅ P(B) ≠ P(A ∩ B)

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2-(-2x-4)=3x+6-x what is the answer to that?

ruslelena [56]

98--8=

Step-by-step explanation:

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3 years ago

Find the general solution of the differential equation and check the result by differentiation. (Use C for the constant of integ

atroni [7]

Answer: $y=Ce^(^3^t^{^9}^)$

Step-by-step explanation:

Beginning with the first differential equation:

$\frac{dy}{dt} =27t^8y$

This differential equation is denoted as a separable differential equation due to us having the ability to separate the variables. Divide both sides by 'y' to get:

$\frac{1}{y} \frac{dy}{dt} =27t^8$

Multiply both sides by 'dt' to get:

$\frac{1}{y}dy =27t^8dt$

Integrate both sides. Both sides will produce an integration constant, but I will merge them together into a single integration constant on the right side:

$\int\limits {\frac{1}{y} } \, dy=\int\limits {27t^8} \, dt$

$ln(y)=27(\frac{1}{9} t^9)+C$

$ln(y)=3t^9+C$

We want to cancel the natural log in order to isolate our function 'y'. We can do this by using 'e' since it is the inverse of the natural log:

$e^l^n^(^y^)=e^(^3^t^{^9} ^+^C^)$

$y=e^(^3^t^{^9} ^+^C^)$

We can take out the 'C' of the exponential using a rule of exponents. Addition in an exponent can be broken up into a product of their bases:

$y=e^(^3^t^{^9}^)e^C$

The term e^C is just another constant, so with impunity, I can absorb everything into a single constant:

$y=Ce^(^3^t^{^9}^)$

To check the answer by differentiation, you require the chain rule. Differentiating an exponential gives back the exponential, but you must multiply by the derivative of the inside. We get:

$\frac{d}{dx} (y)=\frac{d}{dx}(Ce^(^3^t^{^9}^))$

$\frac{dy}{dx} =(Ce^(^3^t^{^9}^))*\frac{d}{dx}(3t^9)$

$\frac{dy}{dx} =(Ce^(^3^t^{^9}^))*27t^8$

Now check if the derivative equals the right side of the original differential equation:

$(Ce^(^3^t^{^9}^))*27t^8=27t^8*y(t)$

$Ce^(^3^t^{^9}^)*27t^8=27t^8*Ce^(^3^t^{^9}^)$

QED

I unfortunately do not have enough room for your second question. It is the exact same type of differential equation as the one solved above. The only difference is the fractional exponent, which would make the problem slightly more involved. If you ask your second question again on a different problem, I'd be glad to help you solve it.

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2 years ago

A ball is thrown from an initial height of 4 feet with an initial upward velocity of 17ft/s. The ball's height h (in feet) after

iVinArrow [24]

Use quadratic formula
8= 4 +17t -16t^2
16t^2 - 17 t + 4
answers (17 + square root (33)) /32 and (17 - square root (33)) /32

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3 years ago

An office needs to order carpet for a waiting room measuring 30 ft. by 24ft. The carpet is sold in square yards. How many square

Dahasolnce [82]

First thing first is to know that there are 3 feel in one yard
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The answer is 80 square yards

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3 years ago

For an essay contest, Annika needs to write 400 words with an absolute deviation of less than 10 words. Using w as a variable, w

saw5 [17]

Answer:

The absolute value inequality to represent the situation is presented as follows;

$\left | w -400 \right |$

Step-by-step explanation:

The given information are;

The number of words Annika needs to write = 400 words

The absolute deviation of the number of words Annika needs to write = 10 words

When we let the number of words Annika write = w, we have;

The absolute value inequality given that the absolute deviation of the number of words is 10 is given as follows;

$\left | w -400 \right |$

Therefore we have;

$\left | w -400 \right |$ gives the statement, -10 < w - 400 < 10.

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3 years ago