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Finding the Fourth Proportional to 247.78, 371.79 and 139.54

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Solution

The fourth proportional to 247.78, 371.79 and 139.54 is: 209.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    247.78 : 371.79 = 139.54 : x
  2. Step 2: Convert to fraction form
    247.78/371.79 = 139.54/x
  3. Step 3: Cross multiply
    247.78x = 371.79 × 139.54
  4. Step 4: Simplify right side
    247.78x = 51,879.58
  5. Step 5: Solve for x
    x = 51,879.58/247.78
  6. Step 6: Final answer
    x = 209.38

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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.