An automobile service facility specializing in engine tune-ups

knows that 45% of all tune-ups are done on fourcylinder

automobiles, 40% on six-cylinder automobiles, and 15% on eight-

cylinder automobiles. Let X= the number of cylinders on the next

car to be tuned.

a.

What is the pmf of

X

b.

Draw both a line graph and a probability histogram for the pmf of

part (a).

c.

What is the probability that the next car tuned has at least six

cylinders? More than six cylinders?