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Question :
11.Which of the following not a required condition for a : 1329667

11.Which of the following is __not__ a required condition for a discrete probability function?

a.f(*x*) ? 0 for all values of *x*

b.?f(*x*) ? 1

c.?f(*x*) ? 0

d.All of the answers are correct.

12.Which of the following statements about a discrete random variable and its probability distribution are true?

a.Values of the random variable can never be negative.

b.Negative values of f(*x*) are allowed as long as ?f(*x*) ? 1.

c.Values of f(*x*) must be greater than or equal to zero.

d.The values of f(*x*) increase to a maximum point and then decrease.

13.A measure of the average value of a random variable is called a(n)

a.variance

b.standard deviation

c.expected value

d.None of the answers is correct.

14.A weighted average of the value of a random variable, where the probability function provides weights is known as

a.a probability function

b.a random variable

c.the expected value

d.None of the answers is correct

15.The expected value of a random variable is the

a.value of the random variable that should be observed on the next repeat of the experiment

b.value of the random variable that occurs most frequently

c.square root of the variance

d.None of the answers is correct.

16.The expected value of a discrete random variable

a.is the most likely or highest probability value for the random variable

b.will always be one of the values *x* can take on, although it may not be the highest probability value for the random variable

c.is the average value for the random variable over many repeats of the experiment

d.All of the answers are correct.

17.Excel's __________ function can be used to compute the expected value of a discrete random variable.

a.SUMPRODUCT

b.AVERAGE

c.MEDIAN

d.VAR

18.Variance is

a.a measure of the average, or central value of a random variable

b.a measure of the dispersion of a random variable

c.the square root of the standard deviation

d.the sum of the deviation of data elements from the mean

19.The variance is a weighted average of the

a.square root of the deviations from the mean

b.square root of the deviations from the median

c.squared deviations from the median

d.squared deviations from the mean

20.Excel's __________ function can be used to compute the variance of a discrete random variable.

a.SUMPRODUCT

b.AVERAGE

c.MEDIAN

d.VAR