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Finding the Fourth Proportional to 137.09, 189.16 and 78.05

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Solution

The fourth proportional to 137.09, 189.16 and 78.05 is: 107.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.09 : 189.16 = 78.05 : x
  2. Step 2: Convert to fraction form
    137.09/189.16 = 78.05/x
  3. Step 3: Cross multiply
    137.09x = 189.16 × 78.05
  4. Step 4: Simplify right side
    137.09x = 14,764.02
  5. Step 5: Solve for x
    x = 14,764.02/137.09
  6. Step 6: Final answer
    x = 107.70

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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.