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Finding the Fourth Proportional to 115.56, 172.86 and 72.12

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Solution

The fourth proportional to 115.56, 172.86 and 72.12 is: 107.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.56 : 172.86 = 72.12 : x
  2. Step 2: Convert to fraction form
    115.56/172.86 = 72.12/x
  3. Step 3: Cross multiply
    115.56x = 172.86 × 72.12
  4. Step 4: Simplify right side
    115.56x = 12,466.66
  5. Step 5: Solve for x
    x = 12,466.66/115.56
  6. Step 6: Final answer
    x = 107.88

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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.