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Finding the Fourth Proportional to 25.31, 37.90 and 20.20

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Solution

The fourth proportional to 25.31, 37.90 and 20.20 is: 30.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.31 : 37.90 = 20.20 : x
  2. Step 2: Convert to fraction form
    25.31/37.90 = 20.20/x
  3. Step 3: Cross multiply
    25.31x = 37.90 × 20.20
  4. Step 4: Simplify right side
    25.31x = 765.58
  5. Step 5: Solve for x
    x = 765.58/25.31
  6. Step 6: Final answer
    x = 30.25

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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.