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Finding the Fourth Proportional to 641.88, 885.78 and 393.30

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Solution

The fourth proportional to 641.88, 885.78 and 393.30 is: 542.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.88 : 885.78 = 393.30 : x
  2. Step 2: Convert to fraction form
    641.88/885.78 = 393.30/x
  3. Step 3: Cross multiply
    641.88x = 885.78 × 393.30
  4. Step 4: Simplify right side
    641.88x = 348,377.27
  5. Step 5: Solve for x
    x = 348,377.27/641.88
  6. Step 6: Final answer
    x = 542.75

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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.