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Finding the Fourth Proportional to 215.72, 323.34 and 138.68

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Solution

The fourth proportional to 215.72, 323.34 and 138.68 is: 207.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.72 : 323.34 = 138.68 : x
  2. Step 2: Convert to fraction form
    215.72/323.34 = 138.68/x
  3. Step 3: Cross multiply
    215.72x = 323.34 × 138.68
  4. Step 4: Simplify right side
    215.72x = 44,840.79
  5. Step 5: Solve for x
    x = 44,840.79/215.72
  6. Step 6: Final answer
    x = 207.87

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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.