1)Develop realistic examples of pairs of random variables for which you would expect to find the following:

a.Positive covariance (for example, amount of time studying and score on test should have a positive covariance; what is another example?)

b.Negative covariance

c. Zero covariance

2) A furniture manufacturer has found that the time spent by workers assembling a particular table follows a normal distribution with a mean of 150 minutes and a standard deviation of 40 minutes.

a.The probability is 0.9 that a randomly chosen table requires more than how many minutes to assembler?

b.What is the probability that a randomly chosen table can be assembled in fewer than 183.6 minutes?

c. A sample of 10 tables are chosen at random.What is the probability that the mean time for assembly for the sample of 10 tables will be fewer than 183.6 minutes?