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Finding the Fourth Proportional to 641.89, 885.60 and 392.95

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Solution

The fourth proportional to 641.89, 885.60 and 392.95 is: 542.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.89 : 885.60 = 392.95 : x
  2. Step 2: Convert to fraction form
    641.89/885.60 = 392.95/x
  3. Step 3: Cross multiply
    641.89x = 885.60 × 392.95
  4. Step 4: Simplify right side
    641.89x = 347,992.09
  5. Step 5: Solve for x
    x = 347,992.09/641.89
  6. Step 6: Final answer
    x = 542.14

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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.