eco 221 test one qs
The weight of an object, measured in grams, is an example of _____.
a continuous random variable
The binomial probability distribution is used with _____.
a discrete random variable
The number of customers who enter a store during one day is an example of _____.
a discrete random variable
Positive values of covariance indicate _____.
a positive relation between the x and y variable
The union of events A and B is the event containing _____.
all the sample points belonging to A or B or both
The correlation coefficient _____.
cannot be larger than 1
When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the _____.
classical method
The _____ denotes the number of standard deviations xi is from the mean .
coefficient of variation
Posterior probabilities are _____.
conditional probabilities
The random variable x is the number of occurrences of an event over an interval of 10 minutes. It can be assumed the probability of an occurrence is the same in any two time periods of an equal length. It is known that the mean number of occurrences in 10 minutes is 5.3. Refer to Exhibit 5-11. The appropriate probability distribution for the random variable is _____.
discrete
A sample point refers to a(n) _____.
individual outcome of an experiment
The symbol ∩ shows the _____.
intersection of events
The coefficient of variation indicates how large the standard deviation is relative to the _____.
mean
The probability of the intersection of two mutually exclusive events _____.
must always be equal to 0
During a cold winter, the temperature stayed below zero for 10 days (ranging from -20 to -5). The variance of the temperatures of the 10 day period _____.
must be at least zero
Which of the following symbols represents the size of a sample?
n
The numerical value of the standard deviation can never be _____.
negative
The interquartile range is _____.
the difference between the third and first quartiles
Which of the following is NOT a measure of location?
variance
Which of the following symbols represents the variance of a population?
σ 2
Which of the following is not a measure of dispersion?
50th percentile
The 50th percentile is the _____.
The 50th percentile is the _____.
If P(A ∩ B) = 0, _____.
A and B are mutually exclusive events
Events A and B are mutually exclusive. Which of the following statements is also true?
P(A ∪ B) = P(A) + P(B)
The complement of P(A | B) is _____.
P(A^c | B)
Which of the following is a characteristic of a binomial experiment?
The trials are independent.
If r = 0.48 for data set A and r = -0.48 for data set B, which of the following is true?
The two data sets have the same level of correlation
A(n) __________ is a collection of sample points.
event
An element of the sample space is a(n) _____.
sample point