The Dubuque Cement Company packs 80-pound bags of concrete mix. Time-study data for the filling activity are shown in the following table. Because of the high physical demands of the job, the company%u2019s policy is a 23% allowance for workers.

a) Compute the standard time for the bag-packing task.
b) How many observations are necessary for 99% confidence,
within 5% accuracy?

         Element        Observations (seconds)    Performance Rating (%)
                                    1     2     3    4        5

Grasp and place bag   8     9     8   11       7                110
Fill bag                       36    41   39 35 112a                 85
Seal bag                    15    17   13   20    18                105
Place bag on conveyor 8    6     9   30b 35b                 90

a. Bag breaks open; included as delay in the allowance factor.
b. Conveyor jams; included as delay in the allowance factor.

Problem 5-23

Consider the following time series data.

(a)	Choose the correct time series plot.
	(i) (ii)         (iii) (iv)
	_________________
	What type of pattern exists in the data?
	_________________
(b)	Use a multiple regression model with dummy variables as follows to develop an equation to account for seasonal effects in the data. Qtr1 = 1 if Quarter 1, 0 otherwise; Qtr2 = 1 if Quarter 2, 0 otherwise; Qtr3 = 1 if Quarter 3, 0 otherwise.
	If required, round your answers to three decimal places. For subtractive or negative numbers use a minus sign even if there is a + sign before the blank. (Example: -300)
	Value = __________6.667_______ + ___-1______________ Qtr1t + _____-3____________ Qtr2t + __________-2_______ Qtr3t
(c)	Compute the quarterly forecasts for next year based on the model you developed in part (b).
	If required, round your answers to three decimal places.
	Quarter 1 forecast _____5.667____________ Quarter 2 forecast _____3.667____________ Quarter 3 forecast _______4.667__________ Quarter 4 forecast ______6.667___________
(d)	Use a multiple regression model to develop an equation to account for trend and seasonal effects in the data. Use the dummy variables you developed in part (b) to capture seasonal effects and create a variable t such that t = 1 for Quarter 1 in Year 1, t = 2 for Quarter 2 in Year 1,… t = 12 for Quarter 4 in Year 3.
	If required, round your answers to three decimal places. For subtractive or negative numbers use a minus sign even if there is a + sign before the blank. (Example: -300)
	Value =   3.4167______________ + __0.2188______________ Qtr1t + _____-2.1875___________ Qtr2t + __-1.5938_______________ Qtr3t + ___0.4063______________ t
(e)	Compute the quarterly forecasts for next year based on the model you developed in part (d).
	Round your interim computations and final answers to three decimal places.
	Quarter 1 forecast _8.9167________________ Quarter 2 forecast ___6.9167______________ Quarter 3 forecast 7.9167_________________ Quarter 4 forecast _9.9167________________
(f)	Is the model you developed in part (b) or the model you developed in part (d) more effective?
	If required, round your intermediate calculations and final answer to three decimal places.
	Model developed in part (b) Model developed in part (d) MSE _________________ _________________
I only need (f) answered
	I only need (f) answered Both MSE needs to be included for part (b) and (d).

7.

Identify the types of information that are necessary to communicate with emergency responders.

Select one or more:

• How the incident happened

• Any chemicals involved in an incident

• Any other hazards present in the lab

• The history of safety incidents in the lab

10. In lab, you may need to evaluate the odor or smell of a chemical.

What is the best way to smell a chemical sample?

Select one:

• Vigorously shake the sample until the smell travels to you.

• Hold the sample under your nose and slowly sniff.

• Use your hand to gently waft the smell toward you.

• Put your head in a fume hood as you heat the sample in it.

11. In general, which characteristics are necessary for a location to be suitable for chemical storage?

Select one or more:

• dark

• poorly-ventilated

• warm

• dry

• cool

17. When should lab participants look at the Safety Data Sheet (SDS) of a substance?

Select one:

• While working with the substance in lab

• Only if the substance is perceived to be dangerous

• Before using the substance

• After completing work with the substance

22. Which is NOT a good source of information about the hazards that affect waste disposal in a chemistry lab?

Select one:

• The chemical Safety Data Sheets

• Your instructor’s directions

• The chemical bottle labels

• Your lab partner

25. When should you start a new chemical waste container in the lab?

Select one:

• When you accidentally spill chemicals down the side of the current container

• When the contents of the current container completely fill the container to the brim

• When the contents of the current container are a couple inches below the brim of the container

• When you need to dispose of another chemical that is compatible with chemicals in the current container

29. What should you do every time before you leave the lab?

Select one or more:

• Remove your gloves.

• Wash your hands.

• Turn off the lights.

• Remove your labcoat, if you are wearing one.

33. Determine when you should remove your goggles in the lab room.

Select one:

• When everyone in the room is done handling any chemicals or glassware

• Whenever your goggles become foggy or uncomfortable

• Whenever you need to lean in close to get a volume reading

• When you have finished cleaning up your chemicals and glassware

Consider the following time series data.

1. Construct a time series plot. What type of pattern exists in the data?

   
   

   The time series plot indicates a linear trend and a seasonal pattern

2. Show the four-quarter and centered moving average values for this time series.

    

3. Compute seasonal indexes and adjusted seasonal indexes for the four quarters.

S7.12 The three-station work cell at Pullman Mfg., Inc. is illustrated in Figure S7.8. It has two machines at station 1 in par- allel (i.e., the product needs to go through only one of the two machines before proceeding to station 2). a) What is the throughput time of this work cell? b) What is the bottleneck time of this work cell? c) What is the bottleneck station?d) If the firm operates 8 hours per day, 6 days per week, what is
the weekly capacity of this work cell?

Station 1 Machine A

20units/hr

Station 1 Machine B

20 units/hr

Station 2

12 units/hr

Station 3

8 units/hr

Consider a file currently consisting of 200 blocks. Assume that the file control block (and the index block, in the case of indexed allocation) is already in memory. Calculate how many disk I/O operations are required for contiguous, linked, and indexed (single-level) allocation strategies, if the following conditions hold. In the contiguous allocation case, assume that there is no room to grow in the beginning, but there is room to grow in the end. Assume that the block information to be added is stored in memory. For linked allocation, there is a tail pointer pointing to the last node.

1. The block is added at the beginning
2. The block is added at the end
3. The block is removed from the beginning
4. The block is removed from the end

More Assumptions:

• Read one whole block = one I/O operation

• Write one whole block = one I/O operation

• For linked allocation, a file allocation table (FAT) is not used, i.e., only the address of the starting block is in memory

• All preparation of a block (including putting in the data and any link value) is done in main memory and then the block is written to disk with one write operation

• The file control block does not have to be written to disk after a change (this is typical where many operations are performed on a file)

• At most one index block is required per file and it does not have to be written to disk after a change.

• For contiguous, linked and indexed allocations, assume that no I/O operations are necessary to add a freed block to the free list

Note that while calculating the total number of I/O operations for each, also indicate how many came from r(read) and w(write).