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Finding the Fourth Proportional to 920.28, 1,380.87 and 509.43

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Solution

The fourth proportional to 920.28, 1,380.87 and 509.43 is: 764.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.28 : 1,380.87 = 509.43 : x
  2. Step 2: Convert to fraction form
    920.28/1,380.87 = 509.43/x
  3. Step 3: Cross multiply
    920.28x = 1,380.87 × 509.43
  4. Step 4: Simplify right side
    920.28x = 703,456.60
  5. Step 5: Solve for x
    x = 703,456.60/920.28
  6. Step 6: Final answer
    x = 764.39

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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.