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Finding the Fourth Proportional to 390.87, 539.49 and 351.46

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Solution

The fourth proportional to 390.87, 539.49 and 351.46 is: 485.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.87 : 539.49 = 351.46 : x
  2. Step 2: Convert to fraction form
    390.87/539.49 = 351.46/x
  3. Step 3: Cross multiply
    390.87x = 539.49 × 351.46
  4. Step 4: Simplify right side
    390.87x = 189,609.16
  5. Step 5: Solve for x
    x = 189,609.16/390.87
  6. Step 6: Final answer
    x = 485.10

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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.