The following model is a simplified version of the multiple regression model used by Biddle and Hamermesh (1990) to study the tradeoff between time spent sleeping and working and to look at other factors affecting sleep: sleep = β0 + β1totwrk + β2educ + β3age + u,

where sleep and totwrk (total work) are measured in minutes per week and educ and age are measured in years.

1. If adults trade off sleep for work, what is the sign of β1?
2. What signs do you think β2 and β3 will have?
3. Using the data in SLEEP75.RAW, the estimated equation is

= 3,638.25 - .148 totwrk - 11.13 educ + 2.20 age n = 706, R2 = .113.

If someone works five more hours per week, by how many minutes is sleep predicted to fall? Is this a large tradeoff?

4. Discuss the sign and magnitude of the estimated coefficient on educ.
5. Would you say totwrk, educ, and age explain much of the variation in sleep? What other factors might affect the time spent sleeping? Are these likely to be correlated with totwrk?

The following cost data relate to the manufacturing activities of chang company during the just completed year: manufacturing overhead costs incurred: indirect materials $ 15,800 indirect labor 138,000 property taxes, factory 8,800 utilities, factory 78,000 depreciation, factory 150,600 insurance, factory 10,800 total actual manufacturing overhead costs incurred $ 402,000 other costs incurred: purchases of raw materials (both direct and indirect) $ 408,000 direct labor cost $ 68,000 inventories: raw materials, beginning $ 20,800 raw materials, ending $ 30,800 work in process, beginning $ 40,800 work in process, ending $ 70,800 the company uses a predetermined overhead rate of $20 per machine-hour to apply overhead cost to jobs. a total of 20,500 machine-hours were used during the year. required: 1. compute the amount of underapplied or overapplied overhead cost for the year. 2. prepare a schedule of cost of goods manufactured for the year.

Needs to schedule the staffing of the center. it is open from 8am until midnight. larry has monitored the usage of the center at various times of the day and determined that the following number of computer consultants are required: time of dayminimum number of consultants required to be on duty8 am-noon4noon-4 pm84pm-8pm108pm-midnight6 two types of computer consultants can be hired: full-time and part-time. the full- time consultants work for eight consecutive hours in any of the shifts: morning (8am- 4pm), afternoon (noon-8pm) and evening (4pm-midnight). full-time consultants are paid $14 per hour. part-time consultants can be hired to work any of the four shifts listed in the table. part-time consultants are paid $12 per hour. an additional requirement is that during every time period, there must be at least two full-time consultants on duty for every part-time consultant on duty. larry would like to determine how many full-time and part-time consultants should work each shift to meet the above requirements at the minimum possible cost. formulate this as an lp problem. you must define your variables clearly

Who is not spending wisely? erika goes shopping and saves her receipts. she totals how much she spent and writes it down. mia needs to buy a new pair of shoes because she joined the soccer team. she looks at newspaper ads to find the best price. lauren has been thinking about getting a puppy for a long time. she walks by the pet store at the mall and decides to get a puppy. erin makes a purchase online using a credit card. she knows that she can pay the entire bill when it arrives.