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Finding the Fourth Proportional to 38.87, 58.23 and 20.78

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Solution

The fourth proportional to 38.87, 58.23 and 20.78 is: 31.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.87 : 58.23 = 20.78 : x
  2. Step 2: Convert to fraction form
    38.87/58.23 = 20.78/x
  3. Step 3: Cross multiply
    38.87x = 58.23 × 20.78
  4. Step 4: Simplify right side
    38.87x = 1,209.73
  5. Step 5: Solve for x
    x = 1,209.73/38.87
  6. Step 6: Final answer
    x = 31.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.