Advertisements
Advertisements
Question
The average number of phone calls per minute into the switchboard of a company between 10.00 am and 2.30 pm is 2.5. Find the probability that during one particular minute there will be exactly 3 calls
Advertisements
Solution
The average number of phone cells per minute into the switchboard of a company is λ = 2.5
x follows poisson distribution with
P(x) = `("e"^(-lambda) lambda^x)/(x!)`
= `((2^(-2.5) (2.5)^x)/(x!))`
P(exactly 3 calls) = P(X = 3)
= `("e^(-2.5) (2.5)^3)/3`
= `((0.08208) xx 15.625)/6`
= 0.2138
APPEARS IN
RELATED QUESTIONS
If 5% of the items produced turn out to be defective, then find out the probability that out of 20 items selected at random there are exactly 4 defectives
Forty percent of business travellers carry a laptop. In a sample of 15 business travelers, what is the probability that atleast three of the travelers have a laptop?
An experiment succeeds twice as often as it fails, what is the probability that in next five trials there will be at least three successes
Mention the properties of poisson distribution
The mortality rate for a certain disease is 7 in 1000. What is the probability for just 2 deaths on account of this disease in a group of 400? [Given e–2.8 = 0.06]
Choose the correct alternative:
Which of the following statements is/are true regarding the normal distribution curve?
Choose the correct alternative:
Cape town is estimated to have 21% of homes whose owners subscribe to the satellite service, DSTV. If a random sample of your home is taken, what is the probability that all four homes subscribe to DSTV?
Choose the correct alternative:
Monthly expenditure on their credit cards, by credit cardholders from a certain bank, follows a normal distribution with a mean of ₹ 1,295.00 and a standard deviation of ₹ 750.00. What proportion of credit cardholders spend more than ₹ 1,500.00 on their credit cards per month?
Vehicles pass through a junction on a busy road at an average rate of 300 per hour. What is the expected number passing in two minutes?
The time taken to assemble a car in a certain plant is a random variable having a normal distribution of 20 hours and a standard deviation of 2 hours. What is the probability that a car can be assembled at this plant in a period of time. Between 20 and 22 hours?
