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Finding the Fourth Proportional to 205.14, 307.48 and 81.72

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Solution

The fourth proportional to 205.14, 307.48 and 81.72 is: 122.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.14 : 307.48 = 81.72 : x
  2. Step 2: Convert to fraction form
    205.14/307.48 = 81.72/x
  3. Step 3: Cross multiply
    205.14x = 307.48 × 81.72
  4. Step 4: Simplify right side
    205.14x = 25,127.27
  5. Step 5: Solve for x
    x = 25,127.27/205.14
  6. Step 6: Final answer
    x = 122.49

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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.