The plastic arrow on a spinner for a childs game stops rotat

The plastic arrow on a spinner for a childs game stops rotating to point at a color that will determine what happens next. Are the given probability assignments possible?

Red Yellow Green Blue

a) 1, 0,0,0

b) 0.7, 0.1, 0.1, 0.1

c) 0.25, 0.25, 0.25, 0.25

d) 0.4, 0.2, 0.2, 0.6

e) 0.5, 0.2, 1.1, -1.8

Select all that are possible.

Solution

a. Possible. Probabilities must sum to 1.

b. Possible.

c. Possible.

d. Impossible. The sum of the probabilities is greater than 1.

e. Impossible. An event cannot have a negative probability.