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Finding the Fourth Proportional to 641.91, 885.84 and 389.84

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Solution

The fourth proportional to 641.91, 885.84 and 389.84 is: 537.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.91 : 885.84 = 389.84 : x
  2. Step 2: Convert to fraction form
    641.91/885.84 = 389.84/x
  3. Step 3: Cross multiply
    641.91x = 885.84 × 389.84
  4. Step 4: Simplify right side
    641.91x = 345,331.44
  5. Step 5: Solve for x
    x = 345,331.44/641.91
  6. Step 6: Final answer
    x = 537.97

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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.