The waiting time at an elevator is uniformly distributed between 40 and 300 seco

Question

The waiting time at an elevator is uniformly distributed between 40 and 300 seconds. Mean _____ Find the mean and standard deviation of the waiting time. Std.dev _____ The probability is The waiting time at an elevator is uniformly distributed between 40 and 300 seconds. _____ What is the probability a rider must wait between 2 minute and 4 minutes? The probability is The waiting time at an elevator is uniformly distributed between 40 and 300seconds. _____ What is the probability a rider waits less than 3 minutes?

Explanation / Answer

1. For unifrormly distribution given are 2 limits:

a=40 seconds; b=300 sec

mean= (a+b)/2= 340/2 = 170 sec

std dev= (b-a)/sqrt(12) = (300-40)/sqrt(12) = 75.056 sec

2. P(120<X<240) =P(X<240) - P(X<120)

P(X<240) = (x-a)/(b-a) = (240-40)/(300-40) =0.769

P(X<120) = (120-40)/(300-40) =0.308

THUS,

P(120<X<240) =0.769-0.308 = 0.461

3. P(X<180) = (x-a)/(b-a) = (180-40)/(300-40)=0.538

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.