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Finding the Fourth Proportional to 154.72, 212.18 and 138.32

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Solution

The fourth proportional to 154.72, 212.18 and 138.32 is: 189.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.72 : 212.18 = 138.32 : x
  2. Step 2: Convert to fraction form
    154.72/212.18 = 138.32/x
  3. Step 3: Cross multiply
    154.72x = 212.18 × 138.32
  4. Step 4: Simplify right side
    154.72x = 29,347.78
  5. Step 5: Solve for x
    x = 29,347.78/154.72
  6. Step 6: Final answer
    x = 189.68

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.