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Finding the Fourth Proportional to 172.12, 257.76 and 137.80

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Solution

The fourth proportional to 172.12, 257.76 and 137.80 is: 206.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.12 : 257.76 = 137.80 : x
  2. Step 2: Convert to fraction form
    172.12/257.76 = 137.80/x
  3. Step 3: Cross multiply
    172.12x = 257.76 × 137.80
  4. Step 4: Simplify right side
    172.12x = 35,519.33
  5. Step 5: Solve for x
    x = 35,519.33/172.12
  6. Step 6: Final answer
    x = 206.36

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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.