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Finding the Fourth Proportional to 921.96, 1,381.34 and 487.80

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Solution

The fourth proportional to 921.96, 1,381.34 and 487.80 is: 730.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.96 : 1,381.34 = 487.80 : x
  2. Step 2: Convert to fraction form
    921.96/1,381.34 = 487.80/x
  3. Step 3: Cross multiply
    921.96x = 1,381.34 × 487.80
  4. Step 4: Simplify right side
    921.96x = 673,817.65
  5. Step 5: Solve for x
    x = 673,817.65/921.96
  6. Step 6: Final answer
    x = 730.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.