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Finding the Fourth Proportional to 203.78, 281.13 and 138.35

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Solution

The fourth proportional to 203.78, 281.13 and 138.35 is: 190.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    203.78 : 281.13 = 138.35 : x
  2. Step 2: Convert to fraction form
    203.78/281.13 = 138.35/x
  3. Step 3: Cross multiply
    203.78x = 281.13 × 138.35
  4. Step 4: Simplify right side
    203.78x = 38,894.34
  5. Step 5: Solve for x
    x = 38,894.34/203.78
  6. Step 6: Final answer
    x = 190.86

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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.