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Finding the Fourth Proportional to 154.10, 211.68 and 138.78

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Solution

The fourth proportional to 154.10, 211.68 and 138.78 is: 190.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.10 : 211.68 = 138.78 : x
  2. Step 2: Convert to fraction form
    154.10/211.68 = 138.78/x
  3. Step 3: Cross multiply
    154.10x = 211.68 × 138.78
  4. Step 4: Simplify right side
    154.10x = 29,376.95
  5. Step 5: Solve for x
    x = 29,376.95/154.10
  6. Step 6: Final answer
    x = 190.63

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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.