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Finding the Fourth Proportional to 138.03, 190.47 and 85.57

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Solution

The fourth proportional to 138.03, 190.47 and 85.57 is: 118.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.03 : 190.47 = 85.57 : x
  2. Step 2: Convert to fraction form
    138.03/190.47 = 85.57/x
  3. Step 3: Cross multiply
    138.03x = 190.47 × 85.57
  4. Step 4: Simplify right side
    138.03x = 16,298.52
  5. Step 5: Solve for x
    x = 16,298.52/138.03
  6. Step 6: Final answer
    x = 118.08

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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.