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Finding the Fourth Proportional to 385.64, 578.45 and 129.14

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Solution

The fourth proportional to 385.64, 578.45 and 129.14 is: 193.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.64 : 578.45 = 129.14 : x
  2. Step 2: Convert to fraction form
    385.64/578.45 = 129.14/x
  3. Step 3: Cross multiply
    385.64x = 578.45 × 129.14
  4. Step 4: Simplify right side
    385.64x = 74,700.39
  5. Step 5: Solve for x
    x = 74,700.39/385.64
  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.