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Finding the Fourth Proportional to 25.25, 34.78 and 20.87

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Solution

The fourth proportional to 25.25, 34.78 and 20.87 is: 28.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.25 : 34.78 = 20.87 : x
  2. Step 2: Convert to fraction form
    25.25/34.78 = 20.87/x
  3. Step 3: Cross multiply
    25.25x = 34.78 × 20.87
  4. Step 4: Simplify right side
    25.25x = 725.86
  5. Step 5: Solve for x
    x = 725.86/25.25
  6. Step 6: Final answer
    x = 28.75

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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.