The objectives of this experiment are to: • define a refrigeration cycle and quantitative measures of its performance. • evaluate the performance of a cycle based on experimental measurements.

1. To evaluate the performance of a new diagnostic test for disease X, the developer performed a trial on 100 people known to have disease X and 95 of them have positive test results. The test is also performed on 200 control cases known to be free of disease X and 30 of them have positive test results. Based on these data, what is the sensitivity and specificity of the test? (10 marks) 2. Based on all the information currently available, you estimate that Mr. Chen has a 0.2 probability of having disease Y. You order a diagnostic test for disease Y which has a sensitivity of 95% and a specificity of 85%. (a) Suppose that the result comes back positive. Based on all the information now available, what is the probability that Mr. Chen has disease Y? Compute your answer to at least 4 decimal places. (5 marks) (b) On the other hand, suppose that the result comes back negative. Based on all the information now available, what is the probability that Mr. Chen has disease Y? Compute your answer to at least 4 decimal places. (5 marks) 3. A test with 95% sensitivity and 85% specificity is used to screen a population of 10,000 people for disease Z. Previous studies indicated that this population has a 10% prevalence rate for disease Z. What is the expected number of people in the population that will have test results that are correct? (5 marks)

The objectives of this experiment are to: • define a refrigeration cycle and quantitative measures of its performance. • evaluate the performance of a cycle based on experimental measurements.

Problem 5: A traffic control engineer believes that the cars passing through a particular intersection arrive at a mean rate equal to either 3 or 5 for a given time interval. Prior to collecting any data, the engineer believes that it is much more likely that the rate λ = 3 than λ = 5. In fact, the engineer believes that the prior probabilities are: P(λ = 3) = 0.7 and P(λ = 5) = 0.3 One day, during a randomly selected time interval, the engineer observes x = 7 cars pass through the intersection. In light of the engineer's observation, what is the probability that λ = 3? And what is the probability that λ = 5?

Problem 4: A coin is thrown independently 10 times to test the hypothesis that the probability of heads is 0.5 versus the alternative that the probability is not 0.5. The test rejects if either 0 or 10 heads are observed. What is the significance level of the test?

Problem 3: Let X be a binomial random variable with n trials and probability p of success. What is the generalized likelihood ratio for testing Ho: p = 0.5 versus H₁:p # 0.5?

Problem 2: Currently, 20% of potential customers buy soap of brand A. To increase sales, the company will conduct an extensive advertising campaign. At the end of the campaign, a sample of 400 potential customers will be interviewed to determine whether the campaign was successful. a) State Ho and H₁ in terms of p, the probability that a customer prefers soap brand A. b) The company decides to conclude that the advertising campaign was a success if at least 92 of the 400 customers interviewed prefer brand A. Find a. (Use the normal approximation to the binomial distribution to evaluate the desired probability.)

Problem 2: Let the unknown probability that a basketball player makes a shot successfully be 0. Suppose your prior on 9 is uniform on [0, 1] and that she then makes two shots in a row. Assume that the outcomes of the two shots are independent. a) What is the posterior density of ? b) What would you estimate the probability that she makes a third shot to be?