The arrival time of an elevator in a 12-story dormitory is equally likely at any time range during the next 4.6 minutes. a. Calculate the expected arrival time. (Round your answer to 2 decimal place.) b. What is the probability that an elevator arrives in less than 3.5 minutes? (Round intermediate calculations to at least 4 decimal places and final answer to 3 decimal places.) c. What is the probability that the wait for an elevator is more than 3.5 minutes? (Round intermediate calculations to at least 4

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Answer:

a. 2.30 minutes

b. 0.761

c. 0.239

Step-by-step explanation:

Since this is a uniform distribution, the probability distribution function for any given time between 0 and 4.6 minutes is:

[tex]P(X \leq x)=\frac{x-0}{4.6-0}=\frac{x}{4.6}[/tex]

a. The expected arrival time is the average waiting time, at an uniform distribution, the average is:

[tex]E(X) = \frac{4.6+0}{2}=2.30\ minutes[/tex]

b. The probability for X ≤ 3.5 is:

[tex]P(X \leq 3.5)=\frac{3.5}{4.6} \\P(X \leq 3.5)=0.761[/tex]

c. The probability for X ≥ 3.5 is:

[tex]P(X \geq 3.5)=1-P(X \leq 3.5)=1-0.761\\P(X \geq 3.5)=0.239[/tex]

Using the uniform distribution, it is found that:

a) The expected arrival time is of 2.3 minutes.

b) There is a 0.7609 = 76.09% probability that an elevator arrives in less than 3.5 minutes.

c) There is a 0.2391 = 23.91% probability that the wait for an elevator is more than 3.5 minutes.

What is the uniform probability distribution?

It is a distribution with two bounds, a and b, in which each outcome is equally as likely.

The expected value of the uniform distribution is given by:

[tex]E(X) = \frac{a + b}{2}[/tex]

The probability of finding a value of at lower than x is:

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

The probability of finding a value above x is:

[tex]P(X > x) = \frac{b - x}{b - a}[/tex]

In this problem, the arrival time is equally likely at any time range during the next 4.6 minutes, hence a = 0, b = 4.6.

Item a:

[tex]E(X) = \frac{0 + 4.6}{2} = 2.3[/tex]

The expected arrival time is of 2.3 minutes.

Item b:

[tex]P(X < 3.5) = \frac{3.5 - 0}{4.6 - 0} = 0.7609[/tex]

There is a 0.7609 = 76.09% probability that an elevator arrives in less than 3.5 minutes.

Item c:

[tex]P(X > 3.5) = \frac{4.6 - 3.5}{4.6 - 0} = 0.2391[/tex]

There is a 0.2391 = 23.91% probability that the wait for an elevator is more than 3.5 minutes.

More can be learned about the uniform distribution at https://brainly.com/question/13889040

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