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Finding the Fourth Proportional to 447.78, 671.71 and 139.63

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Solution

The fourth proportional to 447.78, 671.71 and 139.63 is: 209.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    447.78 : 671.71 = 139.63 : x
  2. Step 2: Convert to fraction form
    447.78/671.71 = 139.63/x
  3. Step 3: Cross multiply
    447.78x = 671.71 × 139.63
  4. Step 4: Simplify right side
    447.78x = 93,794.09
  5. Step 5: Solve for x
    x = 93,794.09/447.78
  6. Step 6: Final answer
    x = 209.46

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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.