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Finding the Fourth Proportional to 178.78, 268.36 and 138.64

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Solution

The fourth proportional to 178.78, 268.36 and 138.64 is: 208.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    178.78 : 268.36 = 138.64 : x
  2. Step 2: Convert to fraction form
    178.78/268.36 = 138.64/x
  3. Step 3: Cross multiply
    178.78x = 268.36 × 138.64
  4. Step 4: Simplify right side
    178.78x = 37,205.43
  5. Step 5: Solve for x
    x = 37,205.43/178.78
  6. Step 6: Final answer
    x = 208.11

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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.