A bag contains four red marbles, five green marbles and six blue marbles, all of which are indistinguishable except for their colour. Three marbles are selected randomly from the bag WITHOUT replacement. What is the probability that at least one of the selected marbles is red?
Select one:
a. 0.8154
b. 0.6374
c. 0.4747
d. 0.4835
e. 0.7363
Write s for the standard deviation of the random sample 6, 8, 7, 4 and 6. If we add 5 to each of these numbers and calculate the standard deviation of the new numbers, it will equal
Select one:
a. We cannot answer - we need more information
b. s + 5
c. 5s
d. s
e. 25s