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Finding the Fourth Proportional to 485.12, 727.59 and 138.38

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Solution

The fourth proportional to 485.12, 727.59 and 138.38 is: 207.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.12 : 727.59 = 138.38 : x
  2. Step 2: Convert to fraction form
    485.12/727.59 = 138.38/x
  3. Step 3: Cross multiply
    485.12x = 727.59 × 138.38
  4. Step 4: Simplify right side
    485.12x = 100,680.27
  5. Step 5: Solve for x
    x = 100,680.27/485.12
  6. Step 6: Final answer
    x = 207.54

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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.