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Finding the Fourth Proportional to 217.66, 300.21 and 138.89

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Solution

The fourth proportional to 217.66, 300.21 and 138.89 is: 191.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.66 : 300.21 = 138.89 : x
  2. Step 2: Convert to fraction form
    217.66/300.21 = 138.89/x
  3. Step 3: Cross multiply
    217.66x = 300.21 × 138.89
  4. Step 4: Simplify right side
    217.66x = 41,696.92
  5. Step 5: Solve for x
    x = 41,696.92/217.66
  6. Step 6: Final answer
    x = 191.57

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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.