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Finding the Fourth Proportional to 390.62, 539.04 and 213.57

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Solution

The fourth proportional to 390.62, 539.04 and 213.57 is: 294.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.62 : 539.04 = 213.57 : x
  2. Step 2: Convert to fraction form
    390.62/539.04 = 213.57/x
  3. Step 3: Cross multiply
    390.62x = 539.04 × 213.57
  4. Step 4: Simplify right side
    390.62x = 115,121.70
  5. Step 5: Solve for x
    x = 115,121.70/390.62
  6. Step 6: Final answer
    x = 294.72

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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.