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Finding the Fourth Proportional to 212.31, 292.95 and 129.40

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Solution

The fourth proportional to 212.31, 292.95 and 129.40 is: 178.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.31 : 292.95 = 129.40 : x
  2. Step 2: Convert to fraction form
    212.31/292.95 = 129.40/x
  3. Step 3: Cross multiply
    212.31x = 292.95 × 129.40
  4. Step 4: Simplify right side
    212.31x = 37,907.73
  5. Step 5: Solve for x
    x = 37,907.73/212.31
  6. Step 6: Final answer
    x = 178.55

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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.