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Finding the Fourth Proportional to 71.45, 107.21 and 25.79

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Solution

The fourth proportional to 71.45, 107.21 and 25.79 is: 38.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.45 : 107.21 = 25.79 : x
  2. Step 2: Convert to fraction form
    71.45/107.21 = 25.79/x
  3. Step 3: Cross multiply
    71.45x = 107.21 × 25.79
  4. Step 4: Simplify right side
    71.45x = 2,765.28
  5. Step 5: Solve for x
    x = 2,765.28/71.45
  6. Step 6: Final answer
    x = 38.70

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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.