The probability density function for an exponential random variable x has a graph called a bell curve.
A) True B) False
Q. 2The conditions for both the hypergeometric and the binomial random variables require that each trial results in one of two outcomes.
A) True B) False
Q. 3A confidence interval was used to estimate the proportion of statistics students who are female. A random sample of 72 statistics students generated the following confidence interval: (0.438, 0.642).
Using the information above, what sample size would be necessary if we wanted to estimate the true proportion to within 3 using 99 reliability?
A) 1916 B) 1842 C) 1769 D) 1831
Q. 4The results of a Tukey multiple comparison are summarized below.
Treatment Sample Mean
B 35.4
C 31.5
A 20.7
a. How many pairwise comparisons of the three treatments are there?
b. Which treatments are significantly different from each other?
c. Which treatments are not significantly different from each other?
Q. 5The exponential distribution is sometimes called the waiting-time distribution, because it is used to describe the length of time between occurrences of random events.
A) True B) False
Q. 6A bank offers online banking to its customers free of charge. While online, customers can also sign up for additional services that the bank offers. Let x be the number of customers who sign up for additional services online each day.
Suppose the distribution of x is approximated well by a Poisson distribution with mean = 42.3. Find E(x) and interpret its value.
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