Question

The Humber Room advertises two types of entrée, meat and fish. It is known that 70% of all customers order meat, and 30% order fish. All customers are individually asked after their meals if they were satisfied with them. This survey shows that 80% of those who ordered meat and 95% of those who ordered fish were satisfied. Draw a probability tree for this problem to answer the question.If M represents the event of ordering meat, F is the event of ordering fish, + is the event of being satisfied, and − is the event of not being satisfied, then answer the following questions:

Answer 1

P(M)=70%=0.7

P(F)=30% =0.3

Of those who ordered meat

• P(+)=80%=0.8

,

• p(-)=1-0.8=0.2

Of those who ordered fish

• P(+)=95%=0.95

,

• p(-)=1-0.95=0.05

The completed probability tree is attached below: