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Finding the Fourth Proportional to 247.55, 371.20 and 85.21

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Solution

The fourth proportional to 247.55, 371.20 and 85.21 is: 127.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    247.55 : 371.20 = 85.21 : x
  2. Step 2: Convert to fraction form
    247.55/371.20 = 85.21/x
  3. Step 3: Cross multiply
    247.55x = 371.20 × 85.21
  4. Step 4: Simplify right side
    247.55x = 31,627.67
  5. Step 5: Solve for x
    x = 31,627.67/247.55
  6. Step 6: Final answer
    x = 127.77

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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.