1. Suppose that all of the outcomes of a random variable are , and that P(a)=P(b)=P(c)=P(d)= 1/4, (that is, all outcomes a, b, c, and d each have a 1/4 probability of occuring), and P(e)=0. Define the events , , , and . True or false: The events A and C are independent.
True
False
2. Suppose that all of the outcomes of a random variable are , and that P(a)=P(b)=P(c)=P(d)= 1/4, (that is, all outcomes a, b, c, and d each have a 1/4 probability of occuring), and P(e)=0. Define the events a={a,b}, b={b,c}, c={c,d}, and d={e}. Calculate the probability p(a/c).
a- 1/2
b- 1/8
c-0
d-1/3
3. If the coefficient of correlation r=0.80 the standard deviations of x and y are 2 and 0.5, respectively. Then Cov(x,y) must be
a-1.6
b-0.8
c-0.08
d-8
4. Suppose that all of the outcomes of a random variable are , and that P(a)=P(b)=P(c)=P(d)= 1/4, (that is, all outcomes a, b, c, and d each have a 1/4 probability of occuring), and P(e)=0. Define the events , , , and . True or false: The events A and B are independent.
5. Consider a binomial random variable where the probability of success on each trial is 0.7, and there are 10 different trials. what is the probability of having more than 5 successes?/
a-0952
b-0.048
c-0.849
d-0.151