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Finding the Fourth Proportional to 115.40, 173.10 and 80.60

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Solution

The fourth proportional to 115.40, 173.10 and 80.60 is: 120.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.40 : 173.10 = 80.60 : x
  2. Step 2: Convert to fraction form
    115.40/173.10 = 80.60/x
  3. Step 3: Cross multiply
    115.40x = 173.10 × 80.60
  4. Step 4: Simplify right side
    115.40x = 13,951.86
  5. Step 5: Solve for x
    x = 13,951.86/115.40
  6. Step 6: Final answer
    x = 120.90

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.