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Finding the Fourth Proportional to 638.35, 881.17 and 620.80

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Solution

The fourth proportional to 638.35, 881.17 and 620.80 is: 856.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.35 : 881.17 = 620.80 : x
  2. Step 2: Convert to fraction form
    638.35/881.17 = 620.80/x
  3. Step 3: Cross multiply
    638.35x = 881.17 × 620.80
  4. Step 4: Simplify right side
    638.35x = 547,030.34
  5. Step 5: Solve for x
    x = 547,030.34/638.35
  6. Step 6: Final answer
    x = 856.94

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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.