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Finding the Fourth Proportional to 312.15, 430.85 and 207.18

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Solution

The fourth proportional to 312.15, 430.85 and 207.18 is: 285.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.15 : 430.85 = 207.18 : x
  2. Step 2: Convert to fraction form
    312.15/430.85 = 207.18/x
  3. Step 3: Cross multiply
    312.15x = 430.85 × 207.18
  4. Step 4: Simplify right side
    312.15x = 89,262.47
  5. Step 5: Solve for x
    x = 89,262.47/312.15
  6. Step 6: Final answer
    x = 285.96

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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.