ECON 2040 EXAM 3
You have to master the contents on the following chapters to do well in this examination:
• Continuous Probability
... [Show More] Distribution
• Sampling and Sampling Distributions
You should also be thoroughly conversant with the introduction to business statistics.
1) Which of the following experiments does not generate a continuous random variable?
A) measuring the number of ounces of soda in a bottle
B) recording the number of minutes a customer waits on hold for technical support
C) counting the number of customers who enter a store during the business day
D) recording the number of miles traveled between two locations
2) Which of the following probability distribution is not continuous?
A) Poisson
B) normal
C) exponential
D) All of these are continuous probability distributions.
3) The ________ probability distribution is bell-shaped and symmetrical.
A) Poisson
B) normal
C) exponential
D) uniform
4) The ________ probability distribution is used to describe data where lower values tend to dominate and higher values don't occur very often.
A) binomial
B) normal
C) exponential
D) uniform
5) The ________ probability distribution describes data where all the values have the same chance of occurring.
A) discrete
B) normal
C) exponentialD) uniform
6) The ________ probability distribution is useful when the majority of the data tend to be in the middle of the distribution.
A) Poisson
B) normal
C) exponential
D) uniform
7) Which of the following statements is true regarding the normal probability distribution? A) The mean and median are roughly equal to one another.
B) The mean is always greater than the median.
C) The mean is always less than the median.
D) The mean is always greater than the mode.
8) A smaller standard deviation for the normal probability distribution results in a _______________________.
A) fatter curve that is more spread out around the mean and not as tall
B) fatter curve that is tighter and taller around the mean
C) skinnier curve that is tighter and taller around the mean
D) skinnier curve that is more spread out around the mean and not as tall
9) Which of the following statements is true regarding z-scores for the normal probability distribution?
A) z-scores are negative for values of x that are less than the distribution mean.
B) z-scores are positive for values of x that are less than the distribution mean.
C) z-scores are zero for values of x that are less than the distribution mean.
D) z-scores are equal to 1.0 for values of x that are equal to the distribution mean.
10) The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. What is the probability that a randomly selected exam will require less than 20 minutes to grade?
A) 0.3715
B) 0.6328
C) 0.8106
D) 0.9230
11) The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. What is the probability that a randomly selected exam will require more than 15 minutes to grade?
A) 0.3783
B) 0.4548
C) 0.5664D) 0.6217
12) The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. What is the probability that a randomly selected exam will require between 14 and 19 minutes to grade?
A) 0.3175
B) 0.3804
C) 0.4477D) 0.5837
13) The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. The interval around the mean that contains 68% of the times needed to grade exams is ________.
A) 12.1, 20.5
B) 7.9, 24.7
C) 5.8, 26.8
D) 3.7, 28.9
14) John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. What is the probability that the commute time for a randomly selected day will be less than 18 minutes? A) 0.0436
B) 0.0778
C) 0.1271
D) 0.2236
15) John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. What is the probability that the commute time for a randomly selected day will be between 28 and 34 minutes? A) 0.1335
B) 0.2266
C) 0.3249D) 0.4013
16) John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. The interval around the mean that contains 99.7% of the commute times is ________.
A) 21.6, 31.8
B) 16.5, 36.9
C) 11.4, 42.0D) 6.3, 47.1
17) Bob's golf score at his local course follows the normal distribution with a mean of 92.1 and a standard deviation of 3.8. What is the probability that the score on his next round of golf will be less than 100? A) 0.5000
B) 0.7357
C) 0.8665
D) 0.9812
18) Bob's golf score at his local course follows the normal distribution with a mean of 92.1 and a standard deviation of 3.8. What is the probability that the score on his next round of golf will be more than 90? A) 0.5832
B) 0.6591
C) 0.7088D) 0.9370
19) Bob's golf score at his local course follows the normal distribution with a mean of 92.1 and a standard deviation of 3.8. What is the probability that the score on his next round of golf will be between 82 and 89?
A) 0.2022
B) 0.3269
C) 0.3960
D) 0.4832
20) Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. What is the probability that a randomly selected airfare between these two cities will be more than $450 [Show Less]