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Finding the Fourth Proportional to 172.90, 238.85 and 129.77

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Solution

The fourth proportional to 172.90, 238.85 and 129.77 is: 179.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.90 : 238.85 = 129.77 : x
  2. Step 2: Convert to fraction form
    172.90/238.85 = 129.77/x
  3. Step 3: Cross multiply
    172.90x = 238.85 × 129.77
  4. Step 4: Simplify right side
    172.90x = 30,995.56
  5. Step 5: Solve for x
    x = 30,995.56/172.90
  6. Step 6: Final answer
    x = 179.27

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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.