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umka2103 [35]
3 years ago
13

Thetime(inhours)requiredtorepairamachineis an exponentially distributed random variable with parameter λ = 1 . What is 2 (a) the

probability that a repair time exceeds 2 hours? (b) the conditional probability that a repair takes at least 10 hours, given that its duration exceeds 9 hours?
Mathematics
1 answer:
mihalych1998 [28]3 years ago
4 0

Answer:

a) 0.1353

b) 0.3679

Step-by-step explanation:

Let's start by defining the random variable T.

T : ''The time (in hours) required to repair a machine''

T ~ exp (λ)

T ~ exp (1)

The probability density function for the exponential distribution is

(In the equation I replaced λ = L)

f(x)=Le^{-Lx}

With L > 0 and x ≥ 0

In this exercise λ = 1 ⇒

f(x)=e^{-x}

For a)

P(T>2)

P(T>2)=1-P(T\leq 2)

P(T>2)=1-\int\limits^2_0 {e^{-x} } \, dx

P(T>2)=1-(-e^{-2}+1)

P(T>2)=e^{-2}=0.1353

For b)

P(T\geq 10/T>9)

The event (T ≥ 10 / T > 9) is equivalent to the event T ≥ 1 so they have the same probability of occur

P(T\geq 10/T>9)=P(T\geq 1)

P(T\geq 1)=1-P(T

P(T\geq 1)=1-(-e^{-1}+1)=e^{-1}=0.3679

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Hello everyone, I have this question. Please help me.
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Answer:

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1 yards = 3 feet => 3.5 yards = 10.5 feet

To determine how many numbers of reservoirs to reserve 90000, we first need to determine the capacity of each reservoirs (how much liquid one reservoir can contain) - which is equal to the volume.

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<em />

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