1.There is a bag with 62 balls. 31 are blue and 31 are red. In 20 pulls from the bag, 20 balls are red. What is the probability with replacement that the 21st pull will be red?
a).5000
b).2500
c).000000477
d).03125
e) none of the above
2.The lengths of time bank customers must wait for a teller are normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute.
A. What proportion of bank customers waits between 3 and 4 minutes
B. What percentage wait more than 4 minutes?
C. What proportion waits between 1 and 3 minutes?
D. What percentage wait less than 1 minute?