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Finding the Fourth Proportional to 312.21, 468.31 and 129.55

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Solution

The fourth proportional to 312.21, 468.31 and 129.55 is: 194.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.21 : 468.31 = 129.55 : x
  2. Step 2: Convert to fraction form
    312.21/468.31 = 129.55/x
  3. Step 3: Cross multiply
    312.21x = 468.31 × 129.55
  4. Step 4: Simplify right side
    312.21x = 60,669.56
  5. Step 5: Solve for x
    x = 60,669.56/312.21
  6. Step 6: Final answer
    x = 194.32

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.