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Finding the Fourth Proportional to 389.14, 583.78 and 129.12

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Solution

The fourth proportional to 389.14, 583.78 and 129.12 is: 193.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.14 : 583.78 = 129.12 : x
  2. Step 2: Convert to fraction form
    389.14/583.78 = 129.12/x
  3. Step 3: Cross multiply
    389.14x = 583.78 × 129.12
  4. Step 4: Simplify right side
    389.14x = 75,376.00
  5. Step 5: Solve for x
    x = 75,376.00/389.14
  6. Step 6: Final answer
    x = 193.70

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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.