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CS0004 Visual Basic 2082 Mr. Trentini Assignment #4 Rubric Due Date: April 16, 2008 No late papers accepted. Objective: You will create a Visual Basic 2005 project that will read a data file, calculate average GPA, and the difference (+/-) for each student GPA from the average. You are required to use one and two dimentional parallel arrays to store data during execution Assignment Task List 1. Create a VB project named Assign04-082, project and files will be stored in the folder Assign04082 2. Your form will be frmGrades. The data file should be saved as D04_In.txt Use the data shown on the sample form (other side). You are free to design your own project form. Remember to follow the guidelines you have learned. 3. When the user clicks on the Average Score menu option, the average score ( Mean ) and Standard Deviation (SD) should be displayed in labels. 4. When the user clicks on the Difference menu option, the difference between the average score and each student score should be calculated and displayed, by name, in a ListBox. 5. When the user clicks on the Grades menu option, the grades will be calculated using the SD and a Bell Curve as follows. Score >= (Mean >= +2 SD) A Score >= (Mean >= +1 SD) B Score >= (Mean ± 1 SD) C Score >= (Mean <= -1 SD) D Score < (Mean <= -2 SD) F Students Names and grades will be posted in a ListBox and written to an output file (stored in the Bin folder) named D04_Out.txt.. 6. The Sort menu option will allow the user to rearrange the data by last name (Ascending) or Score (Descending) 7. The Search menu option will allow the user to search the data by last name and return via a message box the Grade of the student. If the student is not in the data, an appropriate message should be displayed. Your search must be case insensitive. 8. All of the command buttons and menu items should be able to be activated by using an Access key. 9. The input data file should contain the last name, first name, and Score ( 0 to 100 ) for each student. 10. The output data file will contain the above and the letter grade. 11. The program code will calculate everything else. Note: A different data file will be used for grading. D:\840954591.doc ©2008 Louis Trentini. All rights reserved. 12. Menus for Edit and Data should not be active if the File has not been opened. The Difference menus should not be available until the Average Score has been calculated. Menu for the Grades form; File Edit Data Open File Add student Average Print Delete student Difference Exit Grades Search Sort Name Score 13. Test your executable program (on your media) before turning it in. 14. On the due date you will be responsible for turning in: a. both data files, b. a loaded image of your form, and c. the code. Deductions: Incorrect Folder Name Incorrect Project Name No Executable File Appearance of Interface Standard use of Written Code Program does not meet requirements 5% 5% 5% 5% 10% 70% Data file: D05_In.txt Drawers Baroo Sonite Lichous Knee Clone Beach Steak Dice Utiful Mongous Harmonic Orious Limoni Leer Tree Matto Monize Lution Chester Sue Sam Dee Bo Sy Sandy Chuck John Bea Hugh Phil Greg Al Chandra Paul Tom Si Sol D:\840954591.doc ©2008 Louis Trentini. All rights reserved. 98 79 92 98 67 100 82 91 80 71 61 55 85 74 82 74 91 76 95 Mental Alize Pendus Erachi Nominious Adore Fully Reggy Ann Stu Liv Iggy Steve Will 99 80 61 75 48 79 83 Standard deviation In probability and statistics, the standard deviation of a probability distribution, random variable, or population or multiset of values is a measure of the spread of its values. The standard deviation is usually denoted with the letter σ (lower case sigma). It is defined as the square root of the variance. To understand standard deviation, keep in mind that variance is the average of the squared differences between data points and the mean. Variance is tabulated in units squared. Standard deviation, being the square root of that quantity, therefore measures the spread of data about the mean, measured in the same units as the data. Stated more formally, the standard deviation is the root mean square (RMS) deviation of values from their arithmetic mean. For example, in the population {4, 8}, the mean is 6 and the deviations from mean are {−2, 2}. Those deviations squared are {4, 4} the average of which (the variance) is 4. Therefore, the standard deviation is 2. In this case 100% of the values in the population are at one standard deviation from the mean. The standard deviation is the most common measure of statistical dispersion, measuring how widely spread the values D:\840954591.doc ©2008 Louis Trentini. All rights reserved. in a data set are. If many data points are close to the mean, then the standard deviation is small; if many data points are far from the mean, then the standard deviation is large. If all the data values are equal, then the standard deviation is zero. For a population, the standard deviation can be estimated by a modified standard deviation (s) of a sample. The formulas are given below. Definition and calculation A simple example Suppose we wished to find the standard deviation of the set of the numbers 4 and 8. Step 1: find the arithmetic mean (or average) of 4 and 8, (4 + 8) / 2 = 6. Step 2: find the deviation of each number from the mean, 4−6=−2 8 − 6 = 2. Step 3: square each of the deviations (amplifying larger deviations and making negative values positive), ( − 2)2 = 4 22 = 4. Step 4: sum the obtained squares (as a first step to obtaining an average), 4 + 4 = 8. Step 5: divide the sum by the number of values, which here is 2 (giving an average), 8 / 2 = 4. Step 6: take the non-negative square root of the quotient (converting squared units back to regular units), So, the standard deviation is 2. In other words, the standard deviation of a discrete uniform random variable X can be calculated as follows: 1. For each value xi calculate the difference between xi and the average value . 2. Calculate the squares of these differences. 3. Find the average of the squared differences. This quantity is the variance σ2. 4. Take the square root of the variance. The above expression can also be replaced with D:\840954591.doc ©2008 Louis Trentini. All rights reserved.