Each day a quality engineer selects a random sample of 100 power supplies from the day's production, measures their output voltages, and computes a 90% confidence interval for all the power supplies manufactured that day. What is the probability that on a given day the confidence interval fails to cover the true mean?

Your take on decision making process

In terms of the "great wheel of science", statistics are central to the research process (a) only between the hypothesis phase and the observation phase (b) only between the observation phase and the empirical generalization phase (c) only between the theory phase and the hypothesis phase (d) only between the empirical generalization phase and the theory phase

Which of the following statements is (are) true? i. free entry to a perfectly competitive industry results in the industry's firms earning zero economic profit in the long run, except for the most efficient producers, who may earn economic rent. ii. in a perfectly competitive market, long-run equilibrium is characterized by lmc < p < latc. iii. if a competitive industry is in long-run equilibrium, a decrease in demand causes firms to earn negative profit because the market price will fall below average total cost.