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Finding the Fourth Proportional to 485.26, 727.86 and 138.58

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Solution

The fourth proportional to 485.26, 727.86 and 138.58 is: 207.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.26 : 727.86 = 138.58 : x
  2. Step 2: Convert to fraction form
    485.26/727.86 = 138.58/x
  3. Step 3: Cross multiply
    485.26x = 727.86 × 138.58
  4. Step 4: Simplify right side
    485.26x = 100,866.84
  5. Step 5: Solve for x
    x = 100,866.84/485.26
  6. Step 6: Final answer
    x = 207.86

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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.