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Finding the Fourth Proportional to 217.50, 300.18 and 138.80

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Solution

The fourth proportional to 217.50, 300.18 and 138.80 is: 191.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.50 : 300.18 = 138.80 : x
  2. Step 2: Convert to fraction form
    217.50/300.18 = 138.80/x
  3. Step 3: Cross multiply
    217.50x = 300.18 × 138.80
  4. Step 4: Simplify right side
    217.50x = 41,664.98
  5. Step 5: Solve for x
    x = 41,664.98/217.50
  6. Step 6: Final answer
    x = 191.56

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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.