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Finding the Fourth Proportional to 641.55, 885.16 and 392.61

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Solution

The fourth proportional to 641.55, 885.16 and 392.61 is: 541.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.55 : 885.16 = 392.61 : x
  2. Step 2: Convert to fraction form
    641.55/885.16 = 392.61/x
  3. Step 3: Cross multiply
    641.55x = 885.16 × 392.61
  4. Step 4: Simplify right side
    641.55x = 347,526.48
  5. Step 5: Solve for x
    x = 347,526.48/641.55
  6. Step 6: Final answer
    x = 541.70

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.