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# GRINNELL MAT 209 - Lab2: Breaking the Code – A Graphical Exploration using Bar Charts

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Lab2: Breaking the Code – A Graphical Exploration using Bar ChartsGroup Members: ______________________ _________________________LetterCountLab2: Breaking the Code – A Graphical Exploration using Bar ChartsGroup Members: ______________________ _________________________ ______________________ _________________________Statement of the Problem: Codes have been used by governments for thousands of years to encrypt messages. Deciphered codes have decided the outcome of wars and uncovered assassination attempts. A great deal of time and energy has been spent throughout history on developing and breaking codes. One of the earliest codes was used by Julius Caesar to communicate with his armies. Known as the Caesar Shift, the code is a simple shifting of the alphabet. For instance, a shift of five letters would code the letter a as f, b as g,…, z as e. Your task is to decode the following message using bar charts.Line 1: svukvujhsspunavaolmhyhdhfavduzLine 2: uvddhypzkljshylkhukihaasljvtlkvdu To break this code you will first create a bar chart of non-coded English. Then you will create a bar chart for the frequency of letters in Lines 1 and 2 above. You will compare the two bar charts and hypothesize a shift. (As noted above a shift of 5 letters would mean that the ‘coded’ letter f would be replaced by an a.) Next, check to see if the shift that you hypothesized makes sense. That is, do you get recognizable words as you apply the shift to the coded message. If not, hypothesize a different shift.Strategy to break the code: Using bar charts to break the code involves five steps:- Step I. Create a bar chart of non-coded English.- Step II. Count the frequency of the letters in the coded message.- Step III. Create a bar chart of the coded message.- Step IV. Compare the two bar charts and hypothesize the shift.- Step V. Apply the shift to the coded message.Step I. Create a bar chart of a non-coded reference message.- Type the lower case alphabet under the C1 column and use a label: alphabet- In the second column, type in the counts from the reference message's frequency table given below. - Make a bar chart. (Graphs - Chart) {include appropriate title and labels}- Copy the graph into word.Frequency Table for the reference message.Letter Count Letter Count Letter Count Letter CountA 19 B 2 C 5 D 10E 23 F 3 G 3 H 8I 17 J 3 K 3 L 11M 12 N 23 O 21 P 6Q 0 R 13 S 12 T 20U 7 V 2 W 4 X 0Y 8 Z 0Step II. Count the frequency of the letters in the coded message.- The first person will work with Line 1 of the coded message and fill in column two (Line 1 Frequency) of the table below. The second person will work with Line 2 of the coded message and fill in column three (Line 2 Frequency) of the table.- After both pairs are done, fill in column four (Total Frequency) of the table with the sum of Line 1 Frequency and Line 2 Frequency.The frequency table of the coded message is:Letter Line 1FrequencyLine 2FrequencyTotalFrequencyDecodedLetterABCDEFGHIJKLMNOPQRSTUVWXYZStep III. Create a bar chart of the coded message.- In the third column, type in the counts from the coded message's frequency table. - Make a bar chart. (Graphs - Chart) {include appropriate title and labels}- Copy the graph into word.Step IV. Compare the two bar charts and hypothesize the shift. Fill in column 5 (Decoded Letter)of the table under Step II.Step V. Apply the shift to the coded message. Write the decoded message below.Questions: After you have completed decoding the message, answer each of the following questions in complete sentences.1. Describe the process that you used to compare the two bar charts. Specifically,a. Did you look at the highest peak in each bar chart? This does not work. Why?b. What did you look for in the two bar charts that helped you to break the code?2. Once you decided on a shift, describe how you were able to determine if your hypothesized shift was correct.3. What would you expect to find if you compared the frequency table of the reference message given in step II and a frequency table for another piece of non-coded English of the same

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