Math 1280 Final Exam UPDATED ACTUAL
Questions and CORRECT Answers
Using the value of x from the prior question, what is the SD of x? - CORRECT
ANSWER - 1.94
What is the probably that a randomly selected item from random variable L will be greater than 0
and less than or equal to 3? - CORRECT ANSWER - .57
What is the expectation of random variable L? - CORRECT ANSWER - 1.60
What is the variance of random variable L? - CORRECT ANSWER - 14.58
Which distributions are discrete? - CORRECT ANSWER - Poisson, Binomial, Uniform
What is the expected number of successes when throwing 5 darts? - CORRECT
ANSWER - 0.75
What is the probability of getting 4 or more successes in 5 throws? - CORRECT
ANSWER - .00
A Poisson distribution called Q has an expectation of 4. Which of the following R commands
would tell you the probability that a randomly selected value from Q is less than 6 and greater
than or equal to 4? - CORRECT ANSWER - ppois(5,4) - ppois(3,4)
At a small store, a customer enters the front door on average every 8 minutes. A prior study
indicated that the time between customers entering the front door during weekdays follows an
exponential distribution. What is the probability that the time between customers entering the
store on a weekday will be less than or equal to 7? - CORRECT ANSWER - .58
Questions and CORRECT Answers
Using the value of x from the prior question, what is the SD of x? - CORRECT
ANSWER - 1.94
What is the probably that a randomly selected item from random variable L will be greater than 0
and less than or equal to 3? - CORRECT ANSWER - .57
What is the expectation of random variable L? - CORRECT ANSWER - 1.60
What is the variance of random variable L? - CORRECT ANSWER - 14.58
Which distributions are discrete? - CORRECT ANSWER - Poisson, Binomial, Uniform
What is the expected number of successes when throwing 5 darts? - CORRECT
ANSWER - 0.75
What is the probability of getting 4 or more successes in 5 throws? - CORRECT
ANSWER - .00
A Poisson distribution called Q has an expectation of 4. Which of the following R commands
would tell you the probability that a randomly selected value from Q is less than 6 and greater
than or equal to 4? - CORRECT ANSWER - ppois(5,4) - ppois(3,4)
At a small store, a customer enters the front door on average every 8 minutes. A prior study
indicated that the time between customers entering the front door during weekdays follows an
exponential distribution. What is the probability that the time between customers entering the
store on a weekday will be less than or equal to 7? - CORRECT ANSWER - .58
