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Finding the Fourth Proportional to 137.53, 189.78 and 77.71

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Solution

The fourth proportional to 137.53, 189.78 and 77.71 is: 107.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.53 : 189.78 = 77.71 : x
  2. Step 2: Convert to fraction form
    137.53/189.78 = 77.71/x
  3. Step 3: Cross multiply
    137.53x = 189.78 × 77.71
  4. Step 4: Simplify right side
    137.53x = 14,746.85
  5. Step 5: Solve for x
    x = 14,746.85/137.53
  6. Step 6: Final answer
    x = 107.22

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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.