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Finding the Fourth Proportional to 402.74, 603.95 and 128.76

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Solution

The fourth proportional to 402.74, 603.95 and 128.76 is: 193.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.74 : 603.95 = 128.76 : x
  2. Step 2: Convert to fraction form
    402.74/603.95 = 128.76/x
  3. Step 3: Cross multiply
    402.74x = 603.95 × 128.76
  4. Step 4: Simplify right side
    402.74x = 77,764.87
  5. Step 5: Solve for x
    x = 77,764.87/402.74
  6. Step 6: Final answer
    x = 193.09

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.