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Finding the Fourth Proportional to 172.20, 257.89 and 137.99

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Solution

The fourth proportional to 172.20, 257.89 and 137.99 is: 206.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.20 : 257.89 = 137.99 : x
  2. Step 2: Convert to fraction form
    172.20/257.89 = 137.99/x
  3. Step 3: Cross multiply
    172.20x = 257.89 × 137.99
  4. Step 4: Simplify right side
    172.20x = 35,586.24
  5. Step 5: Solve for x
    x = 35,586.24/172.20
  6. Step 6: Final answer
    x = 206.66

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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.