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Finding the Fourth Proportional to 312.72, 431.31 and 247.11

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Solution

The fourth proportional to 312.72, 431.31 and 247.11 is: 340.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.72 : 431.31 = 247.11 : x
  2. Step 2: Convert to fraction form
    312.72/431.31 = 247.11/x
  3. Step 3: Cross multiply
    312.72x = 431.31 × 247.11
  4. Step 4: Simplify right side
    312.72x = 106,581.01
  5. Step 5: Solve for x
    x = 106,581.01/312.72
  6. Step 6: Final answer
    x = 340.82

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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.