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Finding the Fourth Proportional to 217.30, 299.90 and 138.66

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Solution

The fourth proportional to 217.30, 299.90 and 138.66 is: 191.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.30 : 299.90 = 138.66 : x
  2. Step 2: Convert to fraction form
    217.30/299.90 = 138.66/x
  3. Step 3: Cross multiply
    217.30x = 299.90 × 138.66
  4. Step 4: Simplify right side
    217.30x = 41,584.13
  5. Step 5: Solve for x
    x = 41,584.13/217.30
  6. Step 6: Final answer
    x = 191.37

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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.