Unformatted text preview: n.
= 1.3, 2.4 ± 1.3 = (1.1, 3.7) - 2, 3 (.2965) + (.2541) = .5506 AACSB: Analytical Studies
Topic: Binomial 126. Suppose that x has a hypergeometric distribution with N = 10, r = 5 and n = 3. Calculate
the mean of the distribution.
n (r/N) = 3 (5/10) = 1.5 AACSB: Analytical Studies
Topic: Hypergeometric Distribution 1-435 Chapter 01 - An Introduction to Business Statistics 127. Suppose that x has a hypergeometric distribution with N = 10, r = 5 and n = 3. Calculate
the standard deviation of the distribution.
n (r/N) (1 - r/N) ((N-n)/(N-1)) = 3 (5/10) (.5) (7/9) = .583 (variance) √ .583 = .764 std dev AACSB: Analytical Studies
Topic: Hypergeometric Distribution 128. If in a hypergeometric distribution r is 300, N = 600 and n = 150, estimate the binomial
probability of success.
r/N = 300/600 = 0.500 AACSB: Analytical Studies
Topic: Hypergeometric Distribution Chapter 06
Continuous Random Variables
True / False Questions 1. A uniform distribution f(x) is a continuous probability distribution which says the
probability that x is in any 2 intervals of equal length is the same.
True False 1-436 Chapter 01 - An Introduction to Business Statistics 2. The mean and median are the same for a normal distribution.
True False 3. The mean and median are the same for an exponential distribution.
True False 4. In a statistical study, the random variable X = 1, if the house is colonial, and X = 0 if the
house is not colonial, then it can be stated that the random variable is continuous.
True False 5. The actual weight of hamburger patties is an example of a continuous random variable.
True False 6. The number of defective pencils in a lot of 1000 is an example of a continuous random
True False 7. For a continuous distribution, P(X ≤ 100) = P(X < 100).
True False 1-437 Chapter 01 - An Introduction to Business Statistics 8. All continuous random variables are normally distributed.
True False 9. For a continuous distribution, the exact probability of a particular value is zero.
True False 10. The height of a probability curve f(x) at a particular point indicates the value of a
probability for a given value of a random variable x.
True False 11. A continuous probability distribution having a rectangular shape where the probability is
evenly distributed over an interval of numbers is called a uniform probability distribution.
True False 12. The exponential probability distribution is based on a continuous random variable.
True False 13. The mean of a standard normal distribution is always equal to 1.
True False 14. The standard deviation of a standard normal distribution is always equal to 1.
True False 15. The normal probability distribution is a discrete probability distribution.
True False 1-438 Chapter 01 - An Introduction to Business Statistics 16. A continuous random variable may assume only integer values in a given interval.
True False 17. The z value tells us the number of standard deviations that a value x is from the mean.
True False 18. If the random variable of x is normally distributed, 68.26% of all possible observed values
of x will be within two standard deviations of the mean.
True False 19. For a binomial probability experiment, with n = 150 and p = .2, it is appropriate to use the
normal approximation to the binomial distribution.
True False Multiple Choice Questions 20. The mean life of pair of shoes is 40 months with a standard deviation of 8 months. If the
life of the shoes is normally distributed, how many pairs of shoes out of one million will need
replacement before 36 months?
D. 308,500 21. A standard normal distribution has a mean of _____ and standard deviation of _____.
A. zero, zero
B. zero, one
C. one, one
D. one, zero 1-439 Chapter 01 - An Introduction to Business Statistics 22. A property of continuous distributions is that:
A. As with discrete random variables, the probability distribution can be approximated by a
B. Probabilities for continuous variables can be approximated using discrete random
C. Unlike discrete random variables, probabilities can be found using tables.
D. Unlike discrete random variables, the probability that a continuous random variable equals
a specific value is zero [P(X = x) = 0]. 23. The _____________ distribution would most likely be used to describe the distribution of
time between arrivals of customers at the grocery store.
E. Uniform 24. The area under the normal curve between z = 0 and z = 1 is ________________ the area
under the normal curve between z = 1 and z = 2.
A. Less than
B. Greater than
C. Equal to
D. A, B, or C above dependent on the value of the mean
E. A, B, or C above dependent on the value...
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