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Finding the Fourth Proportional to 137.87, 190.28 and 78.07

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Solution

The fourth proportional to 137.87, 190.28 and 78.07 is: 107.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.87 : 190.28 = 78.07 : x
  2. Step 2: Convert to fraction form
    137.87/190.28 = 78.07/x
  3. Step 3: Cross multiply
    137.87x = 190.28 × 78.07
  4. Step 4: Simplify right side
    137.87x = 14,854.59
  5. Step 5: Solve for x
    x = 14,854.59/137.87
  6. Step 6: Final answer
    x = 107.74

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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.