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Finding the Fourth Proportional to 392.80, 585.80 and 385.12

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Solution

The fourth proportional to 392.80, 585.80 and 385.12 is: 574.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.80 : 585.80 = 385.12 : x
  2. Step 2: Convert to fraction form
    392.80/585.80 = 385.12/x
  3. Step 3: Cross multiply
    392.80x = 585.80 × 385.12
  4. Step 4: Simplify right side
    392.80x = 225,603.30
  5. Step 5: Solve for x
    x = 225,603.30/392.80
  6. Step 6: Final answer
    x = 574.35

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.