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Finding the Fourth Proportional to 641.82, 885.59 and 393.20

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Solution

The fourth proportional to 641.82, 885.59 and 393.20 is: 542.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.82 : 885.59 = 393.20 : x
  2. Step 2: Convert to fraction form
    641.82/885.59 = 393.20/x
  3. Step 3: Cross multiply
    641.82x = 885.59 × 393.20
  4. Step 4: Simplify right side
    641.82x = 348,217.18
  5. Step 5: Solve for x
    x = 348,217.18/641.82
  6. Step 6: Final answer
    x = 542.55

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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.