During the early morning hours, customers arrive at a branch post office at the average rate of 45 per hour (exponential interarrival times), while clerks can handle transactions on an average of 4 minutes each (exponential). what is the minimum number of clerks needed to keep the average time in the system under 5 minutes?

a. 2
b. 3
c. 4
d. 5
e. 6

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends > a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?

Six years ago, an 80-kw diesel electric set cost $160,000. the cost index for this class of equipment six years ago was 187 and is now 194. the cost-capacity factor is 0.6. the plant engineering staff is considering a 120-kw unit of the same general design to power a small isolated plant. assume we want to add a precompressor, which (when isolated and estimated separately) currently costs $13291. determine the total cost of the 120-kw unit. (hint: skip $ and comma symbols)

jackie's snacks sells fudge, caramels, and popcorn. it sold 12,000 units last year. popcorn outsold fudge by a margin of 2 to 1. sales of caramels were the same as sales of popcorn. fixed costs for jackie's snacks are $14,000. additional information follows: product unit sales prices unit variable cost fudge $5.00 $4.00 caramels $8.00 $5.00 popcorn $6.00 $4.50 the breakeven sales volume in units for jackie's snacks is