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Finding the Fourth Proportional to 25.85, 38.72 and 21.79

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Solution

The fourth proportional to 25.85, 38.72 and 21.79 is: 32.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.85 : 38.72 = 21.79 : x
  2. Step 2: Convert to fraction form
    25.85/38.72 = 21.79/x
  3. Step 3: Cross multiply
    25.85x = 38.72 × 21.79
  4. Step 4: Simplify right side
    25.85x = 843.50
  5. Step 5: Solve for x
    x = 843.50/25.85
  6. Step 6: Final answer
    x = 32.63

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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.