Find the equation of the line.

Suppose you choose a marble from a bag containing 3 red marbles, 5 white marbles, and 4 blue marbles. You return the first marbl

Veseljchak [2.6K]

Answer:

P(red and blue) = 0.1667

Step-by-step explanation:

Let A represent choosing a red marble, there are 3 red marbles

Let B represent choosing a blue marble, there are 4 blue marbles

There are 12 total marbles

Then...

P(A) = 3/12

P(B) = 4/12

choosing the first one, then replacing means the first choice has no effect on the probabilities of the second choice, so the situation is independent.

When calculating the probability of independent events, you multiply the probabilities together. There are 2 scenarios where we can get a red and blue marble..

Choosing a red, then a blue marble, the probability is

(3/12)( 4/12) = 12/144 = 1/12

Choosing a blue, then a red marble, the probability is

(4/12)(3/12) = 12/144 = 1/12

So we have a

(1/12) + (1/12) = 2/12 = 1/6 chance for that to happen, to

P(A and B) = 1/6 = 0.1667

6 0

3 years ago

How is this supposed to be done lol

andrezito [222]

Answer:

i think that is c but if I'm wrong deduct points

7 0

2 years ago

The probability that your call to a service line is answered in less than 30 seconds is 0.75. Assume that your calls are indepen

vfiekz [6]

Answer:

a) 0.2581

b) 0.4148

c) 17

Step-by-step explanation:

For each call, there are only two possible outcomes. Either they are answered in less than 30 seconds. Or they are not. The probabilities for each call are independent. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

In this problem we have that:

$p = 0.75$

a. If you call 12 times, what is the probability that exactly 9 of your calls are answered within 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X = 9)$ when $n = 12$ . So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 9) = C_{12,9}.(0.75)^{9}.(0.25)^{3} = 0.2581$

b. If you call 20 times, what is the probability that at least 16 calls are answered in less than 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X \geq 16)$ when $n = 20$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 16) = C_{20,16}.(0.75)^{16}.(0.25)^{4} = 0.1897$

$P(X = 17) = C_{20,17}.(0.75)^{17}.(0.25)^{3} = 0.1339$

$P(X = 18) = C_{20,18}.(0.75)^{18}.(0.25)^{2} = 0.0669$

$P(X = 19) = C_{20,19}.(0.75)^{19}.(0.25)^{1} = 0.0211$

$P(X = 20) = C_{20,20}.(0.75)^{20}.(0.25)^{0} = 0.0032$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20) = 0.1897 + 0.1339 + 0.0669 + 0.0211 + 0.0032 = 0.4148$

c. If you call 22 times, what is the mean number of calls that are answered in less than 30 seconds? Round your answer to the nearest integer.

The expected value of the binomial distribution is:

$E(X) = np$

In this question, we have $n = 22$

So

$E(X) = 22*0.75 = 16.5$

The closest integer to 16.5 is 17.

7 0

3 years ago

In a horse race, the odds in favor of the first horse winning in an 8-horse race are 2 to 5. The odds against the second horse w

Nataly_w [17]

The probability that the first horse wins is 2/7. The probability that the second horse wins is 3/10. Since the events that the first horse wins and the second horse wins are shared exclusive, the probability that either the first horse or the second horse will win is :

2/7 + 3/10= 41/70

Hope this is correct.

4 0

3 years ago

15. The graph of a linear function, f(x), is shown below. If the line is translated 2 units

Leto [7]

Answer: fx-2 i believe since translating down would subtract two

Step-by-step explanation:

4 0

3 years ago