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Finding the Fourth Proportional to 390.87, 539.44 and 225.18

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Solution

The fourth proportional to 390.87, 539.44 and 225.18 is: 310.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.87 : 539.44 = 225.18 : x
  2. Step 2: Convert to fraction form
    390.87/539.44 = 225.18/x
  3. Step 3: Cross multiply
    390.87x = 539.44 × 225.18
  4. Step 4: Simplify right side
    390.87x = 121,470.54
  5. Step 5: Solve for x
    x = 121,470.54/390.87
  6. Step 6: Final answer
    x = 310.77

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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.