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Finding the Fourth Proportional to 137.28, 189.40 and 78.27

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Solution

The fourth proportional to 137.28, 189.40 and 78.27 is: 107.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.28 : 189.40 = 78.27 : x
  2. Step 2: Convert to fraction form
    137.28/189.40 = 78.27/x
  3. Step 3: Cross multiply
    137.28x = 189.40 × 78.27
  4. Step 4: Simplify right side
    137.28x = 14,823.36
  5. Step 5: Solve for x
    x = 14,823.36/137.28
  6. Step 6: Final answer
    x = 107.98

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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.