Chapter 6 Programming Projects

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1.

Write a program to display a company's payroll report in a list box. The program should read each employee's name, hourly rate, and hours worked from a file and produce a report in the form of the sample run shown in Figure 6.18. Employees should be paid time-and-a-half for hours in excess of 40.

Figure 6.18. Sample output from Programming Project 1.

Payroll Report for week ending 11/17/06
Employee	Hourly Rate	Hours Worked	Gross Pay
Al Adams	$6.50	38	$247.00
Bob Brown	$5.70	50	$313.50
Carol Coe	$7.00	40	$280.00
Final Total			$840.50

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2.

Table 6.6 shows the standard prices for items in a department store. Suppose prices will be reduced for the annual President's Day Sale. The new price will be computed by reducing the old price by 10 percent, rounding up to the nearest dollar, and subtracting 1 cent. If the new price is greater than the old price, the old price is used as the sale price. Write a program to display in a list box the output shown in Figure 6.19.

Table 6.6. President's Day sale.

Item	Original Price
GumShoes	39.00
SnugFoot Sandals	21.00
T-Shirt	7.75
Maine Handbag	33.00
Maple Syrup	6.75
Flaked Vest	24.00
Nightshirt	26.00

Figure 6.19. Output of Programming Project 2.

Item	Sale Price
GumShoes	35.99
SnugFoot Sandals	18.99
T-Shirt	6.99
Maine Handbag	29.99
Maple Syrup	6.75
Flaked Vest	21.99
Nightshirt	23.99

3.

The Rule of 72 is used to make a quick estimate of the time required for prices to double due to inflation. If the inflation rate is r percent, then the Rule of 72 estimates that prices will double in 72/ryears. For instance, at an inflation rate of 6 percent, prices double in about 72/6 or 12 years. Write a program to test the accuracy of this rule. The program should display a table showing, for each value of r from 1 to 20, the rounded value of 72/r and the actual number of years required for prices to double at an r percent inflation rate. (Assume prices increase at the end of each year.) Figure 6.20 shows the first few rows of the output.

Figure 6.20. Rule of 72 used in Programming Project 3.

Interest Rate (%)	Rule of 72	Actual
1	72	70
2	36	36
3	24	24

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4.

Table 6.7 shows the number of bachelor degrees conferred in 1980 and 2002 in certain fields of study. Tables 6.8 and 6.9 show the percentage change and a histogram of 2002 levels, respectively. Write a program that allows the user to display any one of these tables as an option and quit as a fourth option.

Table 6.7. Bachelor degrees conferred in certain fields.

Field of Study	1980	2002
Business and management	184,867	281,330
Computer and info. science	11,154	47,299
Education	118,038	106,383
Engineering	68,893	59,481
Social sciences	103,662	132,874

Source: U.S. National Center of Educational Statistics

Table 6.8. Percentage change in bachelor degrees conferred.

Field of Study	% Change (1980-2002)
Business and management	52.2
Computer and info. science	324.1
Education	-9.9
Engineering	-13.7
Social sciences	28.2

Table 6.9. Bachelor degrees conferred in 2002 in certain fields.

Business and management	**************************** 281,330
Computer and info. science	***** 47,299
Education	*********** 106,383
Engineering	****** 59,481
Social sciences	************* 132,874

5.

Least-Squares Approximation. Table 6.10 shows the 1988 prices of a gallon of gasoline and the amounts of fuel consumed for several countries. Figure 6.21 displays the data as points in the xy plane. For instance, the point with coordinates (1, 1400) corresponds to the USA. Figure 6.21 also shows the straight line that best fits these data in the least-squares sense. (The sum of the squares of the distances of the 11 points from this line is as small as possible.) In general, if(x₁,y₁),(x₂,y₂), ...,(x_n,y_n) are n points in the xy coordinate system, then the least-squares approximation to these points is the line y=mx+b,where

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and

b = ((sum of yⁱ) - m * (sum of xⁱ))/n.

Write a program that calculates and displays the equation of the least-squares line. The program should then allow the user to enter a gasoline price and use the equation of the line to predict the corresponding consumption of fuel. (Place the numeric data from the table in a text file.) A sample run is shown in Figure 6.22.

Table 6.10. A comparison of 1988 gasoline prices and per capita fuel use.

Country	Price per gallon in U.S. Dollars	Tons of Fuel per 1000 Persons	Country	Price per gallon in U.S. Dollars	Tons of Fuel per 1000 Persons
USA	$1.00	1400	France	$3.10	580
W. Ger.	$2.20	620	Norway	$3.15	600
England	$2.60	550	Japan	$3.60	410
Austria	$2.75	580	Denmark	$3.70	570
Sweden	$2.80	700	Italy	$3.85	430
Holland	$3.00	490

Source: World Resources Institute

Figure 6.21. Least-squares fit to data from Table 6.10.

Figure 6.22. Sample run of Programming Project 5.

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6.

Write a program to provide information on the height of a ball thrown straight up into the air. The program should request the initial height, h feet, and the initial velocity, v feet per second, as input. The four options to be provided by buttons are as follows:

1. Determine the maximum height of the ball. Note: The ball will reach its maximum height after v/32 seconds.

2. Determine approximately when the ball will hit the ground. Hint: Calculate the height after every .1 second and observe when the height is no longer a positive number.

3. Display a table showing the height of the ball every quarter second for five seconds or until it hits the ground.

4. Quit.

The formula for the height of the ball aftert seconds, h + v*t - 16*t*t*, should be specified in a user-defined function. (Test the program with v = 148 and h = 0. This velocity is approximately the top speed clocked for a ball thrown by a professional baseball pitcher.)

7.

Depreciation to a Salvage Value of 0. For tax purposes an item may be depreciated over a period of several years, n. With the straight-line method of depreciation, each year the item depreciates by 1/nth of its original value. With the double-declining-balance method of depreciation, each year the item depreciates by 2/nths of its value at the beginning of that year. (In the last year, it is depreciated by its value at the beginning of the year.) Write a program that performs the following tasks:

1. Requests a description of the item, the year of purchase, the cost of the item, the number of years to be depreciated (estimated life), and the method of depreciation. The method of depreciation should be chosen by clicking one of two buttons.
   
   

2. Displays a depreciation schedule for the item similar to the schedule shown in Figure 6.23.
   
   

Figure 6.23. Depreciation schedule for Programming Project 7.

Description: Computer
Year of purchase: 2002
Cost: $2,000.00
Estimated life: 5
Method of depreciation: double-declining-balance
	Value at	Amount Deprec	Total Depreciation
Year	Beg of Yr	During Year	to End of Year
2002	2,000.00	800.00	800.00
2003	1,200.00	480.00	1,280.00
2004	720.00	288.00	1,568.00
2005	432.00	172.80	1,740.80
2006	259.20	259.20	2,000.00

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8.

The Twelve Days of Christmas. Each year, PNC Advisors of Pittsburgh publishes a Christmas price list. See Table 6.11. Write a program that requests an integer from 1 through 12 and then lists the gifts for that day along with that day's cost. On the nth day, the n gifts are 1 partridge in a pear tree, 2 turtle doves, ..., n of the nth item. The program also should give the total cost of all twelve days. As an example, Figure 6.24 shows the output in the list box when the user enters 3.

Table 6.11. Christmas price list for 2005.

Item	Cost	Item	Cost
partridge in a pear tree	104.99	swan-a-swimming	600.00
turtle dove	20.00	maid-a-milking	5.15
French hen	15.00	lady dancing	508.46
calling bird	99.99	lord-a-leaping	403.91
gold ring	65.00	piper piping	186.65
geese-a-laying	50.00	drummer drumming	185.36

The gifts for day 3 are

1 partridge in a pear tree

2 turtle doves

3 french hens

Cost: $189.99

Total cost for the twelve days: $72,608.00