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Finding the Fourth Proportional to 312.55, 431.21 and 207.83

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Solution

The fourth proportional to 312.55, 431.21 and 207.83 is: 286.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.55 : 431.21 = 207.83 : x
  2. Step 2: Convert to fraction form
    312.55/431.21 = 207.83/x
  3. Step 3: Cross multiply
    312.55x = 431.21 × 207.83
  4. Step 4: Simplify right side
    312.55x = 89,617.34
  5. Step 5: Solve for x
    x = 89,617.34/312.55
  6. Step 6: Final answer
    x = 286.73

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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.