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Finding the Fourth Proportional to 205.07, 307.65 and 81.68

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Solution

The fourth proportional to 205.07, 307.65 and 81.68 is: 122.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.07 : 307.65 = 81.68 : x
  2. Step 2: Convert to fraction form
    205.07/307.65 = 81.68/x
  3. Step 3: Cross multiply
    205.07x = 307.65 × 81.68
  4. Step 4: Simplify right side
    205.07x = 25,127.31
  5. Step 5: Solve for x
    x = 25,127.31/205.07
  6. Step 6: Final answer
    x = 122.53

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.