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Finding the Fourth Proportional to 216.80, 299.18 and 129.48

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Solution

The fourth proportional to 216.80, 299.18 and 129.48 is: 178.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.80 : 299.18 = 129.48 : x
  2. Step 2: Convert to fraction form
    216.80/299.18 = 129.48/x
  3. Step 3: Cross multiply
    216.80x = 299.18 × 129.48
  4. Step 4: Simplify right side
    216.80x = 38,737.83
  5. Step 5: Solve for x
    x = 38,737.83/216.80
  6. Step 6: Final answer
    x = 178.68

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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.