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Finding the Fourth Proportional to 212.05, 292.68 and 129.21

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Solution

The fourth proportional to 212.05, 292.68 and 129.21 is: 178.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.05 : 292.68 = 129.21 : x
  2. Step 2: Convert to fraction form
    212.05/292.68 = 129.21/x
  3. Step 3: Cross multiply
    212.05x = 292.68 × 129.21
  4. Step 4: Simplify right side
    212.05x = 37,817.18
  5. Step 5: Solve for x
    x = 37,817.18/212.05
  6. Step 6: Final answer
    x = 178.34

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.