1) Speeds of automobiles on a certain stretch of freeway at 11:00PM are normally distributed with mean 65 mph. 20% of the cars are traveling at speeds between 55 and 65 mph. What percentage of the cars are going faster than 75 mph? (Do not include percentage sign)

2) Many companies "grade on a bell curve" to compare the performance of their managers and professional workers. This forces the use of some low performance ratings, so that not all workers are listed as "above average." Ford Motor Company's "performance management process" for a time assigned 10% A grades, 80% B grades, and 10% C grades to the company's 18,000 managers. Suppose that Ford's performance scores really are Normally distributed. This year, managers with scores less than 110 received C grades and those with scores above 459 received A grades. What are the mean and standard deviation of the scores? (Round to one decimal place. This may take multiple steps. You will need to use the z-score formula)

• mean=?
• Standard Deviation=?

3)

Q1 4 Points Examining the location of accidents on a level, 5-mile bike path shows that they occur uniformly along the length of the path (a "uniform" distribution is a continuous distribution with a flat/even density curve). The figure below displays the density curve that describes the distribution of accidents. Height - 1/5 0 2 3 5 Distance along bike path (miles)