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Finding the Fourth Proportional to 641.32, 885.13 and 405.61

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Solution

The fourth proportional to 641.32, 885.13 and 405.61 is: 559.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.32 : 885.13 = 405.61 : x
  2. Step 2: Convert to fraction form
    641.32/885.13 = 405.61/x
  3. Step 3: Cross multiply
    641.32x = 885.13 × 405.61
  4. Step 4: Simplify right side
    641.32x = 359,014.35
  5. Step 5: Solve for x
    x = 359,014.35/641.32
  6. Step 6: Final answer
    x = 559.81

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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.