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Finding the Fourth Proportional to 216.90, 299.28 and 129.56

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Solution

The fourth proportional to 216.90, 299.28 and 129.56 is: 178.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.90 : 299.28 = 129.56 : x
  2. Step 2: Convert to fraction form
    216.90/299.28 = 129.56/x
  3. Step 3: Cross multiply
    216.90x = 299.28 × 129.56
  4. Step 4: Simplify right side
    216.90x = 38,774.72
  5. Step 5: Solve for x
    x = 38,774.72/216.90
  6. Step 6: Final answer
    x = 178.77

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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.