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Finding the Fourth Proportional to 485.10, 727.66 and 138.43

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Solution

The fourth proportional to 485.10, 727.66 and 138.43 is: 207.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.10 : 727.66 = 138.43 : x
  2. Step 2: Convert to fraction form
    485.10/727.66 = 138.43/x
  3. Step 3: Cross multiply
    485.10x = 727.66 × 138.43
  4. Step 4: Simplify right side
    485.10x = 100,727.81
  5. Step 5: Solve for x
    x = 100,727.81/485.10
  6. Step 6: Final answer
    x = 207.64

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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.