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Finding the Fourth Proportional to 125.20, 172.83 and 81.60

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Solution

The fourth proportional to 125.20, 172.83 and 81.60 is: 112.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    125.20 : 172.83 = 81.60 : x
  2. Step 2: Convert to fraction form
    125.20/172.83 = 81.60/x
  3. Step 3: Cross multiply
    125.20x = 172.83 × 81.60
  4. Step 4: Simplify right side
    125.20x = 14,102.93
  5. Step 5: Solve for x
    x = 14,102.93/125.20
  6. Step 6: Final answer
    x = 112.64

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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.