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Finding the Fourth Proportional to 216.87, 299.30 and 129.54

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Solution

The fourth proportional to 216.87, 299.30 and 129.54 is: 178.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.87 : 299.30 = 129.54 : x
  2. Step 2: Convert to fraction form
    216.87/299.30 = 129.54/x
  3. Step 3: Cross multiply
    216.87x = 299.30 × 129.54
  4. Step 4: Simplify right side
    216.87x = 38,771.32
  5. Step 5: Solve for x
    x = 38,771.32/216.87
  6. Step 6: Final answer
    x = 178.78

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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.