Willow Brook National Bank operates a drive-up teller window that allows customers to complete bank transactions without getting out of their cars. On weekday mornings, arrivals to the drive-up teller window occur at random, with a
mean arrival rate of 24 customers per hour or 0.4 customers per minute. Assume that the service times for the drive-up
teller follow an exponential probability distribution with a mean service rate of 36 customers per hour or 0.6 customers
per minute.
a. What is the probability that no customers are in the system?
b. What is the average number of customers waiting in line?
c. What is the average number of customers in the system?
d. What is the average time a customer spends waiting in line?
e. What is the average time a customer spends in the system?
f. What is the probability that arriving customers will have to wait for service (hint: An arriving customer has to wait
except when no customers are in the system upon their arrival)?

Acrosswalk_when there are no pavement markings.

Lavage rapide is a canadian company that owns and operates a large automatic car wash facility near montreal. the following table provides data concerning the company’s costs: fixed cost per month cost per car washed cleaning supplies $ 0.70 electricity $ 1,400 $ 0.07 maintenance $ 0.15 wages and salaries $ 4,900 $ 0.30 depreciation $ 8,300 rent $ 1,900 administrative expenses $ 1,400 $ 0.03 for example, electricity costs are $1,400 per month plus $0.07 per car washed. the company expects to wash 8,000 cars in august and to collect an average of $6.50 per car washed. the actual operating results for august appear below. lavage rapide income statement for the month ended august 31 actual cars washed 8,100 revenue $ 54,100 expenses: cleaning supplies 6,100 electricity 1,930 maintenance 1,440 wages and salaries 7,660 depreciation 8,300 rent 2,100 administrative expenses 1,540 total expense 29,070 net operating income $ 25,030 required: calculate the company's revenue and spending variances for august.

Mcdonald's fast-food restaurants have a well-designed training program for all new employees. each new employee is supposed to learn how to perform standardized tasks required to maintain mcdonald's service quality. due to labor shortages in some areas, new employees begin work as soon as they are hired and do not receive any off-the-job training. this nonconformity to standards creates