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Finding the Fourth Proportional to 422.87, 580.46 and 390.06

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Solution

The fourth proportional to 422.87, 580.46 and 390.06 is: 535.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.87 : 580.46 = 390.06 : x
  2. Step 2: Convert to fraction form
    422.87/580.46 = 390.06/x
  3. Step 3: Cross multiply
    422.87x = 580.46 × 390.06
  4. Step 4: Simplify right side
    422.87x = 226,412.28
  5. Step 5: Solve for x
    x = 226,412.28/422.87
  6. Step 6: Final answer
    x = 535.42

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.