Exam 5: Some Important Discrete Probability Distributions

The local police department must write,on average,5 tickets a day to keep department revenues at budgeted levels.Suppose the number of tickets written per day follows a Poisson distribution with a mean of 6.5 tickets per day.Interpret the value of the mean.

Instruction 5-5 There are two houses with almost identical characteristics available for investment in two different neighbourhoods with drastically different demographic composition.The anticipated gain in value when the houses are sold in 10 years has the following probability distribution: Returns Probability Neighbourhood A Neighbourhood B .25 -\ 22,500 \ 30,500 .40 \ 10,000 \ 25,000 .35 \ 40,500 \ 10,500 -Referring to Instruction 5-5,what is the standard deviation of the value gain for the house in neighbourhood A?

Instruction 5-8 A major airline keeps a record of the number of mishandled bags per 1,000 customers.In 2011,the airline had 4.06 mishandled bags per 1,000 customers.Assume that the number of mishandled bags has a Poisson distribution. -Referring to Instruction 5-8,what is the probability that in the next 1,000 customers,the airline will have between two and four inclusive mishandled bags?

The variance of the sum of two investments will be equal to the sum of the variances of the two investments when the covariance between the investments is zero.

Instruction 6-7 A company has 125 personal computers.The probability that any one of them will require repair on a given day is 0.15. -A probability distribution is an equation that

Instruction 5-3 The following table contains the probability distribution for X = the number of retransmissions necessary to successfully transmit a 1024K data package through a double satellite media. X 0 1 2 3 P(X) 0.35 0.35 0.25 0.05 -Referring to Instruction 5-3,the mean or expected value for the number of retransmissions is ________.

Instruction 5-5 There are two houses with almost identical characteristics available for investment in two different neighbourhoods with drastically different demographic composition.The anticipated gain in value when the houses are sold in 10 years has the following probability distribution: Returns Probability Neighbourhood A Neighbourhood B .25 -\ 22,500 \ 30,500 .40 \ 10,000 \ 25,000 .35 \ 40,500 \ 10,500 -Referring to Instruction 5-5,what is the variance of the gain in value for the house in neighbourhood B?

The probability of receiving a 911 call on a university campus is the same every day.The probability of having received a 911 call on a single day does not change the probability of receiving a 911 call on any other day.Which of the following distributions would you use to determine the probability that a 911 call will be received next day?

Instruction 5-6 From an inventory of 48 new cars being shipped to local dealerships,corporate reports indicate that 12 have defective radios installed. -Referring to Instruction 5-6,what is the probability out of the 8 new cars it just received that,when each is tested,no more than 2 of the cars have defective radios?

If p remains constant in a binomial distribution,an increase in n will increase the variance.

The number of males selected in a sample of 5 students taken without replacement from a class of 9 females and 18 males has a binomial distribution.

In a game called Taxation and Evasion,a player rolls a pair of dice.If on any turn the sum is 7,11,or 12,the player gets audited.Otherwise,she avoids taxes.Suppose a player takes 5 turns at rolling the dice.The expected number of times she will be audited is ________.

Instruction 5-5 There are two houses with almost identical characteristics available for investment in two different neighbourhoods with drastically different demographic composition.The anticipated gain in value when the houses are sold in 10 years has the following probability distribution: Returns Probability Neighbourhood A Neighbourhood B .25 -\ 22,500 \ 30,500 .40 \ 10,000 \ 25,000 .35 \ 40,500 \ 10,500 -Referring to Instruction 5-5,if you can invest 70% of your money on the house in neighbourhood A and the remaining on the house in neighbourhood B,what is the portfolio risk of your investment?

In a game called Taxation and Evasion,a player rolls a pair of dice.If on any turn the sum is 7,11,or 12,the player gets audited.Otherwise,she avoids taxes.Suppose a player takes 5 turns at rolling the dice.The probability that she gets audited once is ________.

In a game called Taxation and Evasion,a player rolls a pair of dice.If on any turn the sum is 7,11,or 12,the player gets audited.Otherwise,she avoids taxes.Suppose a player takes 5 turns at rolling the dice.The probability that she gets audited no more than 2 times is ________.

Instruction 5-8 A major airline keeps a record of the number of mishandled bags per 1,000 customers.In 2011,the airline had 4.06 mishandled bags per 1,000 customers.Assume that the number of mishandled bags has a Poisson distribution. -Referring to Instruction 5-8,what is the probability that in the next 1,000 customers,the airline will have more than eight mishandled bags?

Instruction 5-5 There are two houses with almost identical characteristics available for investment in two different neighbourhoods with drastically different demographic composition.The anticipated gain in value when the houses are sold in 10 years has the following probability distribution: Returns Probability Neighbourhood A Neighbourhood B .25 -\ 22,500 \ 30,500 .40 \ 10,000 \ 25,000 .35 \ 40,500 \ 10,500 -Referring to Instruction 5-5,if you can invest half of your money on the house in neighbourhood A and the remaining on the house in neighbourhood B,what is the portfolio risk of your investment?

Binomial distribution has ________ properties.

The variance of a discrete random variable is directly related to the standard deviation.

The local police department must write,on average,5 tickets a day to keep department revenues at budgeted levels.Suppose the number of tickets written per day follows a Poisson distribution with a mean of 6.4 tickets per day.Find the probability that less than 6 tickets are written on a randomly selected day from this population.