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Finding the Fourth Proportional to 137.89, 190.38 and 105.31

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Solution

The fourth proportional to 137.89, 190.38 and 105.31 is: 145.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.89 : 190.38 = 105.31 : x
  2. Step 2: Convert to fraction form
    137.89/190.38 = 105.31/x
  3. Step 3: Cross multiply
    137.89x = 190.38 × 105.31
  4. Step 4: Simplify right side
    137.89x = 20,047.44
  5. Step 5: Solve for x
    x = 20,047.44/137.89
  6. Step 6: Final answer
    x = 145.39

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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.