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Finding the Fourth Proportional to 641.61, 885.29 and 408.78

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Solution

The fourth proportional to 641.61, 885.29 and 408.78 is: 564.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.61 : 885.29 = 408.78 : x
  2. Step 2: Convert to fraction form
    641.61/885.29 = 408.78/x
  3. Step 3: Cross multiply
    641.61x = 885.29 × 408.78
  4. Step 4: Simplify right side
    641.61x = 361,886.80
  5. Step 5: Solve for x
    x = 361,886.80/641.61
  6. Step 6: Final answer
    x = 564.03

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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.