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Finding the Fourth Proportional to 216.90, 299.34 and 129.57

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Solution

The fourth proportional to 216.90, 299.34 and 129.57 is: 178.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.90 : 299.34 = 129.57 : x
  2. Step 2: Convert to fraction form
    216.90/299.34 = 129.57/x
  3. Step 3: Cross multiply
    216.90x = 299.34 × 129.57
  4. Step 4: Simplify right side
    216.90x = 38,785.48
  5. Step 5: Solve for x
    x = 38,785.48/216.90
  6. Step 6: Final answer
    x = 178.82

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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.