Mathematics, 18.09.2019 03:00 justinjay0000

In a certain clinical study, 15% of participants were classified as heavy smokers, 25% as light-smokers, and the rest as non-smokers. at the end of the study, the death rates of the heavy and light smokers were 5 and 3 times that of non-smokers, respectively. what is the probability that a randomly selected participant who died by the end of the study was a non-smoker?

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Answer from: Nextlevel3

There is a 28.57% probability that a randomly selected participant who died by the end of the study was a non-smoker.

Step-by-step explanation:

We have the following probabilities:

A 15% probability that a participant is classified as a heavy smoker.

A 25% probability that a participant is classified as a light smoker.

A 100% - 25% - 15% = 60% probability that a participant is classified as a non smoker.

A x% probability that a non smoker dies.

A 3x% probability that a light smoker dies.

A 5x% probability that a heavy smoker dies.

This can be formulated as the following problem:

What is the probability of B happening, knowing that A has happened.

It can be calculated by the following formula

$P = \frac{P(B).P(A/B)}{P(A)}$

Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.

This problem is:

What is the probability of the participant being a non-smoker, given that he died?

P(B) is the probability that the participant is a non smoker. So

P(B) = 0.6

P(A/B) is the probability that the participant dies, given that he is a non smoker. So:

P(A/B) = x

P(A) is the probability that the participant dies:

$P(A) = P_{1} + P_{2} + P_{3}$

$P_{1}$ is the probability that a heavy smoker is selected and that he dies. So:

$P_{1} = 0.15*5x = 0.75x$

$P_{2}$ is the probability that a light smoker is selected and that he dies. So:

$P_{2} = 0.25*3x = 0.75x$

$P_{3}$ is the probability that a non-smoker is selected and that he dies. So:

$P_{3} = 0.60*x = 0.60x$

The probability that a participant dies is:

$P(A) = P_{1} + P_{2} + P_{3} = 0.75x + 0.75x + 0.60x = 2.10x$

The probability of the participant being a non-smoker, given that he died, is:

$P = \frac{P(B).P(A/B)}{P(A)} = \frac{0.6x}{2.10x} = \frac{0.6}{2.10} = 0.2857$

There is a 28.57% probability that a randomly selected participant who died by the end of the study was a non-smoker.

Answer from: Quest

The answer would be 13.5 minutes.

Answer from: Quest

step-by-step explanation:

let

we know that

the y-intercept is the y-coordinate of the point when the value of x is equal to zero

the y-coordinate of the point a is the y-intercept

the answer part a) is

the value of y-intercept is

part b) find the slope m

we know that

the value of the slope is equal to

substitute the values

therefore

the answer part b) is

the value of the slope is equal to

the general answer is

the slope is

the value of y-intercept is

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