1. A random sample of 270 customers of an online chat service were surveyed. They were asked a question about the likelihood of them recommending the service to others, and this information was used to classify their attitude as a Detractor, Passive or Advocate. They were also asked how they expect their use of the chat service to change over the coming year. The data is summarized in the contingency table below. (Unfortunately, some of the data is missing from the table.)

	Detractor	Passive	Advocate	TOTAL
Increase	10			71
Stay the same		60	34
Decrease	30	46
TOTAL	55		88	270

Required

1. Fill in the missing numbers.

[2 marks]

1. Determine the probability that a randomly selected customer expects to increase their use of the service over the coming year.

[1 mark]

1. A randomly selected customer is an "advocate". What is the probability that they expect to increase their use of the service over the coming year?

[2 marks]

1. Explain whether attitude and expected usage are independent.

[1 mark]