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Finding the Fourth Proportional to 485.78, 670.11 and 308.44

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Solution

The fourth proportional to 485.78, 670.11 and 308.44 is: 425.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.78 : 670.11 = 308.44 : x
  2. Step 2: Convert to fraction form
    485.78/670.11 = 308.44/x
  3. Step 3: Cross multiply
    485.78x = 670.11 × 308.44
  4. Step 4: Simplify right side
    485.78x = 206,688.73
  5. Step 5: Solve for x
    x = 206,688.73/485.78
  6. Step 6: Final answer
    x = 425.48

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.