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Finding the Fourth Proportional to 172.08, 258.12 and 80.85

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Solution

The fourth proportional to 172.08, 258.12 and 80.85 is: 121.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.08 : 258.12 = 80.85 : x
  2. Step 2: Convert to fraction form
    172.08/258.12 = 80.85/x
  3. Step 3: Cross multiply
    172.08x = 258.12 × 80.85
  4. Step 4: Simplify right side
    172.08x = 20,869.00
  5. Step 5: Solve for x
    x = 20,869.00/172.08
  6. Step 6: Final answer
    x = 121.28

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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.