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Finding the Fourth Proportional to 120.92, 180.40 and 115.12

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Solution

The fourth proportional to 120.92, 180.40 and 115.12 is: 171.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.92 : 180.40 = 115.12 : x
  2. Step 2: Convert to fraction form
    120.92/180.40 = 115.12/x
  3. Step 3: Cross multiply
    120.92x = 180.40 × 115.12
  4. Step 4: Simplify right side
    120.92x = 20,768.13
  5. Step 5: Solve for x
    x = 20,768.13/120.92
  6. Step 6: Final answer
    x = 171.75

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.