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Finding the Fourth Proportional to 213.56, 294.80 and 138.90

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Solution

The fourth proportional to 213.56, 294.80 and 138.90 is: 191.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.56 : 294.80 = 138.90 : x
  2. Step 2: Convert to fraction form
    213.56/294.80 = 138.90/x
  3. Step 3: Cross multiply
    213.56x = 294.80 × 138.90
  4. Step 4: Simplify right side
    213.56x = 40,947.72
  5. Step 5: Solve for x
    x = 40,947.72/213.56
  6. Step 6: Final answer
    x = 191.74

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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.