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Finding the Fourth Proportional to 203.80, 281.13 and 138.40

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Solution

The fourth proportional to 203.80, 281.13 and 138.40 is: 190.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    203.80 : 281.13 = 138.40 : x
  2. Step 2: Convert to fraction form
    203.80/281.13 = 138.40/x
  3. Step 3: Cross multiply
    203.80x = 281.13 × 138.40
  4. Step 4: Simplify right side
    203.80x = 38,908.39
  5. Step 5: Solve for x
    x = 38,908.39/203.80
  6. Step 6: Final answer
    x = 190.91

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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.