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Finding the Fourth Proportional to 312.89, 431.65 and 206.41

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Solution

The fourth proportional to 312.89, 431.65 and 206.41 is: 284.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.89 : 431.65 = 206.41 : x
  2. Step 2: Convert to fraction form
    312.89/431.65 = 206.41/x
  3. Step 3: Cross multiply
    312.89x = 431.65 × 206.41
  4. Step 4: Simplify right side
    312.89x = 89,094.72
  5. Step 5: Solve for x
    x = 89,094.72/312.89
  6. Step 6: Final answer
    x = 284.75

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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.