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Finding the Fourth Proportional to 20.87, 28.78 and 15.04

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Solution

The fourth proportional to 20.87, 28.78 and 15.04 is: 20.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.87 : 28.78 = 15.04 : x
  2. Step 2: Convert to fraction form
    20.87/28.78 = 15.04/x
  3. Step 3: Cross multiply
    20.87x = 28.78 × 15.04
  4. Step 4: Simplify right side
    20.87x = 432.85
  5. Step 5: Solve for x
    x = 432.85/20.87
  6. Step 6: Final answer
    x = 20.74

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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.