STAT200 FINAL EXAM A

1.                  True or False. Justify for full credit.                                                                

(a)If the variance of a data set is zero, then all the observations in this data set are zero.

(b)If P(A) = 0.4 , P(B) = 0.5, and A and B are disjoint, then P(A AND B) = 0.9. 

(c)    Assume X follows a continuous distribution which is symmetric about 0.  If

                                         , then.

(d)   A 95% confidence interval is wider than a 90% confidence interval of the same parameter.

(e)    In a right-tailed test, the value of the test statistic is 1.5. If we know the test statistic follows a Student’s t-distribution with P(T < 1.5) = 0.96, then we fail to reject the null hypothesis at 0.05 level of significance .