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Finding the Fourth Proportional to 638.89, 879.60 and 442.06

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Solution

The fourth proportional to 638.89, 879.60 and 442.06 is: 608.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.89 : 879.60 = 442.06 : x
  2. Step 2: Convert to fraction form
    638.89/879.60 = 442.06/x
  3. Step 3: Cross multiply
    638.89x = 879.60 × 442.06
  4. Step 4: Simplify right side
    638.89x = 388,835.98
  5. Step 5: Solve for x
    x = 388,835.98/638.89
  6. Step 6: Final answer
    x = 608.61

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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.