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Finding the Fourth Proportional to 217.89, 300.65 and 129.38

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Solution

The fourth proportional to 217.89, 300.65 and 129.38 is: 178.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.89 : 300.65 = 129.38 : x
  2. Step 2: Convert to fraction form
    217.89/300.65 = 129.38/x
  3. Step 3: Cross multiply
    217.89x = 300.65 × 129.38
  4. Step 4: Simplify right side
    217.89x = 38,895.95
  5. Step 5: Solve for x
    x = 38,895.95/217.89
  6. Step 6: Final answer
    x = 178.51

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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.