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Finding the Fourth Proportional to 485.13, 727.72 and 138.49

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Solution

The fourth proportional to 485.13, 727.72 and 138.49 is: 207.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.13 : 727.72 = 138.49 : x
  2. Step 2: Convert to fraction form
    485.13/727.72 = 138.49/x
  3. Step 3: Cross multiply
    485.13x = 727.72 × 138.49
  4. Step 4: Simplify right side
    485.13x = 100,781.38
  5. Step 5: Solve for x
    x = 100,781.38/485.13
  6. Step 6: Final answer
    x = 207.74

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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.