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Finding the Fourth Proportional to 769.87, 1,062.41 and 420.55

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Solution

The fourth proportional to 769.87, 1,062.41 and 420.55 is: 580.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    769.87 : 1,062.41 = 420.55 : x
  2. Step 2: Convert to fraction form
    769.87/1,062.41 = 420.55/x
  3. Step 3: Cross multiply
    769.87x = 1,062.41 × 420.55
  4. Step 4: Simplify right side
    769.87x = 446,794.42
  5. Step 5: Solve for x
    x = 446,794.42/769.87
  6. Step 6: Final answer
    x = 580.35

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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.