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Finding the Fourth Proportional to 641.12, 885.04 and 420.08

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Solution

The fourth proportional to 641.12, 885.04 and 420.08 is: 579.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.12 : 885.04 = 420.08 : x
  2. Step 2: Convert to fraction form
    641.12/885.04 = 420.08/x
  3. Step 3: Cross multiply
    641.12x = 885.04 × 420.08
  4. Step 4: Simplify right side
    641.12x = 371,787.60
  5. Step 5: Solve for x
    x = 371,787.60/641.12
  6. Step 6: Final answer
    x = 579.90

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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.