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Finding the Fourth Proportional to 138.07, 190.45 and 85.63

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Solution

The fourth proportional to 138.07, 190.45 and 85.63 is: 118.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.07 : 190.45 = 85.63 : x
  2. Step 2: Convert to fraction form
    138.07/190.45 = 85.63/x
  3. Step 3: Cross multiply
    138.07x = 190.45 × 85.63
  4. Step 4: Simplify right side
    138.07x = 16,308.23
  5. Step 5: Solve for x
    x = 16,308.23/138.07
  6. Step 6: Final answer
    x = 118.12

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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.