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Finding the Fourth Proportional to 385.92, 578.88 and 129.42

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Solution

The fourth proportional to 385.92, 578.88 and 129.42 is: 194.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.92 : 578.88 = 129.42 : x
  2. Step 2: Convert to fraction form
    385.92/578.88 = 129.42/x
  3. Step 3: Cross multiply
    385.92x = 578.88 × 129.42
  4. Step 4: Simplify right side
    385.92x = 74,918.65
  5. Step 5: Solve for x
    x = 74,918.65/385.92
  6. Step 6: Final answer
    x = 194.13

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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.