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Finding the Fourth Proportional to 148.80, 221.94 and 138.72

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Solution

The fourth proportional to 148.80, 221.94 and 138.72 is: 206.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    148.80 : 221.94 = 138.72 : x
  2. Step 2: Convert to fraction form
    148.80/221.94 = 138.72/x
  3. Step 3: Cross multiply
    148.80x = 221.94 × 138.72
  4. Step 4: Simplify right side
    148.80x = 30,787.52
  5. Step 5: Solve for x
    x = 30,787.52/148.80
  6. Step 6: Final answer
    x = 206.91

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.