Author: Anonymous

A professor wants to estimate the percentage of students who pass a stat class. Based on the previous experience, the professor guesses that about 80% will pass the class. How many students must be sampled to estimate the true population proportion within 5% with 95% confidence? 

Accounting department of an airline company claims that 2 out of 10 flights departing from a certain airport are delayed. Suppose you work for the company as a statistical consultant and want to see whether the true proportion of delayed flights is different from what they claim. You randomly selected 120 flights and recorded their flight status. Out of 120 sampled flights, 18 flights were delayed. The p-value of the test is   

For the hypotheses

Students in an introductory chemistry class participate in a mid-semester survey. They were asked whether having recitation classes better prepare them for the course. Their opinions were coded as “0” if the answer was No, “1” if the answer was Somewhat helpful, and “2” if the answer was Yes. This variable is:   

A vending machine sells bottles of coke, diet coke, lemonade, sweet tea, and water.  (a) How many different selections are there for a purchase of 10 bottles, assuming there are more than 10 bottles of each type?Answer: [A] selections (b) If the machine shows that there are only two bottles of coke left for sale (where there are more than 10 bottles of each of the others), how many different selections are there for a purchase of 10 bottles?Answer: [B] selections

Which article correctly agrees with “chicas”

Does this statement agree in number and gender: los estudiantes inteligente  (True- agree, false- disagree)

Does this statement agree in number and gender: el chico alto (True- agree, false- disagree)

Case Scenario K — Harbor Distribution Supply ChainHarbor Distribution manages forecasting, inventory, and quality for a regional distribution center. Recent monthly demand was Month 1: 320 units, Month 2: 360, Month 3: 400, Month 4: 380. For a high-volume SKU, annual demand is 18,000 units, ordering cost is $150 per order, and annual holding cost is $6 per unit; average daily demand is 50 units with a 6-day lead time. On a filling line, a control chart of 25 observations shows 6 consecutive points above the mean but within the control limits, and a Pareto/fishbone study attributes 78% of defects to three root causes.If average daily demand is 50 units and lead time is 6 days, the reorder point (ignoring safety stock) is:

Case Scenario H — Summit Services Management ChallengesSummit Services, a professional-services firm, is preparing a five-year strategic plan, setting team goals, choosing between cost-reduction strategies, addressing turnover among high-performing junior analysts, forming a new cross-functional team, and re-engaging disengaged high performers.Several high performers are disengaged despite above-market base salaries. Per Herzberg’s Two-Factor Theory, the most effective intervention is to: