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Finding the Fourth Proportional to 25.40, 38.07 and 20.88

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Solution

The fourth proportional to 25.40, 38.07 and 20.88 is: 31.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.40 : 38.07 = 20.88 : x
  2. Step 2: Convert to fraction form
    25.40/38.07 = 20.88/x
  3. Step 3: Cross multiply
    25.40x = 38.07 × 20.88
  4. Step 4: Simplify right side
    25.40x = 794.90
  5. Step 5: Solve for x
    x = 794.90/25.40
  6. Step 6: Final answer
    x = 31.29

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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.