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The location of a subway train is uniformly distributed between 30th street and

ID: 3157872 • Letter: T

Question

The location of a subway train is uniformly distributed between 30th street and 80^th street. The probability of the train being at 50^th street or higher is: 0.40 0.50 0.60 0.42 1.00 In a population of students, the number of calculators owned is a random variable X with P(X = 0) = 0.2, P(X = 1) = 0.6, and P(X = 2) = 0.2. What is the mean of the random variable X? 0.0 2.0 1.0 0.5 The answer cannot be computed because it's not continuous. The expected value of x, also known as mu_x, equals the mean mu_x of the population from which the sample is drawn: only if the sample size is 30 or greater only if the sample size is 50 or greater only if the population is not skewed only if the population is Normal for any sample size Which of the following is (are) required condition(s) for a discrete probability function? sigma f(x) = 0 f(x) Greaterthanorequalto 1 for all values of x f(x)

Explanation / Answer

3) the p(0) = 0.2, p(1) = 0.6 +p(2) = 0.2

the mean = E(x) = X1*P(X1)+X2*P(X2)+....+XN*P(XN)

= 0*0,2 +1*0.6+2*0.2

= 1

HENCE OPTION C IS CORRECT