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Finding the Fourth Proportional to 71.21, 106.78 and 25.55

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Solution

The fourth proportional to 71.21, 106.78 and 25.55 is: 38.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.21 : 106.78 = 25.55 : x
  2. Step 2: Convert to fraction form
    71.21/106.78 = 25.55/x
  3. Step 3: Cross multiply
    71.21x = 106.78 × 25.55
  4. Step 4: Simplify right side
    71.21x = 2,727.70
  5. Step 5: Solve for x
    x = 2,727.70/71.21
  6. Step 6: Final answer
    x = 38.31

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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.