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Finding the Fourth Proportional to 312.61, 431.29 and 207.75

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Solution

The fourth proportional to 312.61, 431.29 and 207.75 is: 286.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.61 : 431.29 = 207.75 : x
  2. Step 2: Convert to fraction form
    312.61/431.29 = 207.75/x
  3. Step 3: Cross multiply
    312.61x = 431.29 × 207.75
  4. Step 4: Simplify right side
    312.61x = 89,599.95
  5. Step 5: Solve for x
    x = 89,599.95/312.61
  6. Step 6: Final answer
    x = 286.62

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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.