Most analytical machines used in science can either measure absorbance of light, like the spectrophotometers used in BioZ 151 and 152 labs, or can measure change in electrical conductance.

In order to convert things like absorbance values into concentration data, a linear regression is used.

In order to determine nitrite concentration in water samples, nitrite is reacted with several chemicals to produce a purple color. The absorbance of the solution is measured from known amounts of nitrite to produce a standard curve to analyze samples.

Use the data in the provided table, or from the linked spreadsheet to make a graph and perform a linear regression using treadline.

In order for this to work, samples must be diluted prior to measurement so that the concentration falls within the range of the standard curve. If a sample underwent a 0.01 dilution, and produce an absorbance value of 0.236, what is the resultant concentration of NO₂^- in mg per L? Report your answer to two decimal places.

Tip: The regression equation will give you the final concentration. The dilution is equal to V₁/V₂. The question is asking for the initial concentration.

Suppose the process of producing lightweight parkas by Polly’s Parkas is described by the function q = 10K^0.7(L - 40)^0.3 where q is the number of parkas produced, K the number of computerized stitching-machine hours, and L the number of person-hours of labor. In addition to capital and labor, $15 worth of raw materials is used in the production of each parka.

1. Write total cost function of producing parkas in terms of the quantity produced, and labor and capital used in production.

2. By minimizing cost subject to the production function, derive the cost-minimizing demands for K and L as a function of output (q), wage rates (w), and rental rates on machines (r). Use these results to derive the total cost function: that is, costs as a function of q, r, w, and the constant $10 per unit materials cost.

(Hint: to find the cost function: step 1: set up the minimization problem, with total cost as the objective function, and the constraint production to achieve the quantity q. step 2: Solve the minimization problem using the Lagrange to find the optimal L and K that would achieve the minimum cost. step 3: Substitute the optimal L and K back into the total cost function.)

Scenario 6.1 - The Big Box Bahouth Ltd. is planning for the next two years of production and debating whether to construct a large cross-dock facility with 40 truck bays or a smaller one with 20 truck bays. The cost to build the large facility is $2 million and the cost to build the small one is $1.2 million. If they construct a large facility and demand is as high as they hope, then operating costs are $450,000 annually. If they construct a large facility and demand is low, then operating costs are $300,000. If they construct a small facility and demand is low, the operating costs are $275,000 but if they experience high demand, the operating cost of a small facility increases to $600,000. After having conducted some market research, they feel that the likelihood of high demand is 0.7 and the likelihood of small demand is 0.3. -Suppose the contractor has found some materials on Craigslist that can drop the construction cost of a large facility to $1,500,000. These materials cannot be used in the construction of the small facility, so its price remains as indicated in Scenario 6.1. Determine the likelihood of high demand that would make the decision maker indifferent between the two alternatives for a two year time period.

A) 1.0 B) 0.72 C) 0.92 D) 0.86

A hotel manager is looking to enhance the initial impression that hotel guests have when they check in. Believed to contribute to initial impressions is the time it takes to deliver a guest’s luggage to his or her room after check-in. A random sample of 20 deliveries on a particular day were selected from Wing A of the hotel, and a random sample of 20 deliveries were selected in Wing B (i.e., the Excel tab LUGGAGE).

(a) Identify which type of test is most appropriate for you to use, justify your answer.

(b) Determine whether or not the mean delivery time differs for the two wings of the hotel (use α = .05).

(c) If faster luggage delivery time is positively related to guests’ initial impression, which wing(s) should receive the highest impression ratings?

You have been appointed as the new general manager of a named hotel. The hotel is not performing as expected and is not meeting its target. Your first assignment is to resolve this problem. Describe in details how you would go about addressing this problem. Hint: Describe the data collection approaches you would use (Observation, interviews, surveys, historical research (past 5 years), etc.) and why you chose this specific form of data collection etc.

A hotel manager is looking to enhance the initial impression that hotel guests have when they check in. Believed to contribute to initial impressions is the time it takes to deliver a guest’s luggage to his or her room after check-in. A random sample of 20 deliveries on a particular day were selected from Wing A of the hotel, and a random sample of 20 deliveries were selected in Wing B (i.e., the Excel tab LUGGAGE). (a) Identify which type of test is most appropriate for you to use, justify your answer. (b) Determine whether or not the mean delivery time differs for the two wings of the hotel (use α = .05). (c) If faster luggage delivery time is positively related to guests’ initial impression, which wing(s) should receive the highest impression ratings?

Please use Visual Basic

Hotel Occupancy

The Hotel has 8 Floors and 30 rooms on each floor. Create an application that calculates the occupancy rate for each floor, and the overall occupancy rate for the hotel. The occupancy rate is the percentage of rooms occupied, and may be calculated by dividing the number of rooms occupied by the number of rooms.

For example, if 18 rooms on the 1^st floor are occupied, the Occupancy Rate is as follows:

18/30=0.6 or 60%

For the Overall Occupancy Rate, using the above example,

18/(8*30)=0.075 or 7.5%

Another example for Overall Occupancy Rate:

If 1^st floor, 18 rooms occupied.

2^nd floor, 30 rooms occupied, then the calculation is:

(18+30) /(8*30)   or (18+30)/240 =0.2 or 20%

You will need to use Name Constants for Rooms (30 rooms), and Floors (8 floors).

Some variables and Constants you will need to declare in class level to do the Overall Total and Overall Occupancy Rate calculation.

Some variables you will need to use in the local level.

The application’s form should appear similar to the one shown below.

In the form load event handler, use a loop to populate floor 1 to 8 in combo box. (Do NOT create floor 1 to 8 at design time using the Items property)

On startup, “Select the floor” combo box should default to floor 1. Each time the user enters the occupancy for a single floor and clicks the Save button, the floor number in the Drop-Down List ComboBox should increment automatically (just add 1 to its SelectedIndex property), and a new line should appear in the ListBox with the percentage occupancy. Also, the contents of the TextBox at the top of the form should clear automatically when the user clicks the Save button, so the user does not accidentally enter the same data twice in a row.

The Restart button should clear all the appropriate controls on the form. “Select the floor” combo box should default to floor 1.

The Exit button should end the application.

The Save button should do all input validation and all other calculations. (Do NOT use a loop in the btnSave_click event handler)

Input Validation: Be sure to check for a non-integer value in TextBox using the Integer.TryParse method and notify the user if there is an error. Since each floor has only 30 rooms, you need to do the range check to prevent user enter a value is greater than 30 or a negative number. A zero is allowed to input since it may have no occupancy for the whole floor.

Use the values below to confirm that your application is performing the correct calculations.

Use access key for all buttons’ control.