1. True or False. Justify for full credit.
(a) If the variance from a data set is zero, then all the observations in this data set must
(b) P(A AND A^c ) 1, whereA is the complement of A.
(c) The mean is always equal to the median for a normal distribution.
(d) A 99% confidence interval is wider than a 95% confidence interval of the same
There are 1000 juniors in a college. Among the 1000 juniors, 200 students are in the
STAT200 roster, and 100 students are in the PSYC300 roster. There are 80 students taking
12. What is the probability that a randomly selected junior is taking at least one of these two
courses? (10 pts)
13. What is the probability that a randomly selected junior is taking PSYC300, given that
he/she is taking STAT200? (10 pts)