Find chase's mistake

Waiting on the platform, a commuter hears an announcement that the train is running five minutes late. He assumes the arrival ti

natima [27]

Answer:

D. 91%

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Less than 15 minutes.

Event B: Less than 10 minutes.

We are given the following probability distribution:

$f(T = t) = \frac{3}{5}(\frac{5}{t})^4, t \geq 5$

Simplifying:

$f(T = t) = \frac{3*5^4}{5t^4} = \frac{375}{t^4}$

Probability of arriving in less than 15 minutes:

Integral of the distribution from 5 to 15. So

$P(A) = \int_{5}^{15} = \frac{375}{t^4}$

Integral of $\frac{1}{t^4} = t^{-4}$ is $\frac{t^{-3}}{-3} = -\frac{1}{3t^3}$

Then

$\int \frac{375}{t^4} dt = -\frac{125}{t^3}$

Applying the limits, by the Fundamental Theorem of Calculus:

At $t = 15$ , $f(15) = -\frac{125}{15^3} = -\frac{1}{27}$

At $t = 5$ , $f(5) = -\frac{125}{5^3} = -1$

Then

$P(A) = -\frac{1}{27} + 1 = -\frac{1}{27} + \frac{27}{27} = \frac{26}{27}$

Probability of arriving in less than 15 minutes and less than 10 minutes.

The intersection of these events is less than 10 minutes, so:

$P(B) = \int_{5}^{10} = \frac{375}{t^4}$

We already have the integral, so just apply the limits:

At $t = 10$ , $f(10) = -\frac{125}{10^3} = -\frac{1}{8}$

At $t = 5$ , $f(5) = -\frac{125}{5^3} = -1$

Then

$P(A \cap B) = -\frac{1}{8} + 1 = -\frac{1}{8} + \frac{8}{8} = \frac{7}{8}$

If given the train arrived in less than 15 minutes, what is the probability it arrived in less than 10 minutes?

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{\frac{7}{8}}{\frac{26}{27}} = 0.9087$

Thus 90.87%, approximately 91%, and the correct answer is given by option D.

3 0

3 years ago

What is the solution of the system of equations shown in the graph?

Rudiy27

Answer:

The solution of the system of equations shown in the graph is (2,0)

Step-by-step explanation:

It's easy

You just look for the point of intersections the lines make.

The point is on the number 2 on the x axis, and number 0 on the y axis. Therefore its (2,0).

Happy to help!

3 0

3 years ago

Please help I’ll mark you as brainliest if correct!

Dmitry [639]

Answer:

a. 64, 128, 256 (geometric)

b. 11, 13, 15 (arithmetic)

c. 53, 61, 69 (arithmetic)

Step-by-step explanation:

(a) Each term is twice the previous term. so it is geometric with a common ratio of 2

(b) The difference between each term is 2. So it is arithmetic with a common difference of 2

(c) The difference between each term is 8. So it is arithmetic with a common difference of 8

6 0

1 year ago

Find an equation for the line with the given properties.

s344n2d4d5 [400]

Answer:

y = 2x

Step-by-step explanation:

Slope-Intercept Form: y = mx + b

Step 1: Find slope <em>m</em>

2x - y = -4

-y = -2x - 4

y = 2x + 4

Since the 2 lines are parallel, they have the same slope.

Step 2: Define variables

Slope <em>m</em> = 2

Origin (x-int and y-int) (0, 0)

Step 3: Write parallel linear equation

y = 2x + 0

y = 2x

4 0

3 years ago

NO SENDING VIRUS LINKS

vlabodo [156]

22.99 in

Is the answer

8 0

3 years ago