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Finding the Fourth Proportional to 390.96, 539.58 and 225.18

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Solution

The fourth proportional to 390.96, 539.58 and 225.18 is: 310.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.96 : 539.58 = 225.18 : x
  2. Step 2: Convert to fraction form
    390.96/539.58 = 225.18/x
  3. Step 3: Cross multiply
    390.96x = 539.58 × 225.18
  4. Step 4: Simplify right side
    390.96x = 121,502.62
  5. Step 5: Solve for x
    x = 121,502.62/390.96
  6. Step 6: Final answer
    x = 310.78

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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.