Questions 5 6 and 7 refer to the following setup A store sel

Questions, 5, 6 and 7 refer to the following setup: A store sells three brands of laptops (Laptop A, Laptop B, Laptop C). and two types of printers (Printer 1 and Printer 2). When customers make a purchase, they must select exactly one of the three laptops and exactly one of the two printers. The following table gives the proportions of sales for each possible purchasing option. 5. Suppose that a customer who will make a purchase is selected at random. What is the probability they will buy Laptop B or Printer 1? 6. Suppose it is known that a randomly selected customer will purchase Laptop C. What is the probability they will select Printer 1?

Solution

5.

As

P(B) = 0.12 + 0.22 = 0.34
P(1) = 0.12 + 0.12+ 0.06 = 0.30
P(1 and B) = 0.12

And

P(B or 1) = P(B) + P(1) - P(1 and B)

Then

P(B or 1) = 0.52 [ANSWER]

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6.

Note that

P(1 | C) = P(1 and C) / P(C)

As

P(1 and C) = 0.06
P(C) = 0.06 + 0.20 = 0.26

Then

P(1 | C) = 0.23077 [ANSWER]