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Finding the Fourth Proportional to 138.07, 190.64 and 103.49

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Solution

The fourth proportional to 138.07, 190.64 and 103.49 is: 142.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.07 : 190.64 = 103.49 : x
  2. Step 2: Convert to fraction form
    138.07/190.64 = 103.49/x
  3. Step 3: Cross multiply
    138.07x = 190.64 × 103.49
  4. Step 4: Simplify right side
    138.07x = 19,729.35
  5. Step 5: Solve for x
    x = 19,729.35/138.07
  6. Step 6: Final answer
    x = 142.89

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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.