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Finding the Fourth Proportional to 212.10, 292.78 and 138.39

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Solution

The fourth proportional to 212.10, 292.78 and 138.39 is: 191.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.10 : 292.78 = 138.39 : x
  2. Step 2: Convert to fraction form
    212.10/292.78 = 138.39/x
  3. Step 3: Cross multiply
    212.10x = 292.78 × 138.39
  4. Step 4: Simplify right side
    212.10x = 40,517.82
  5. Step 5: Solve for x
    x = 40,517.82/212.10
  6. Step 6: Final answer
    x = 191.03

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.