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Finding the Fourth Proportional to 72.20, 108.28 and 20.83

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Solution

The fourth proportional to 72.20, 108.28 and 20.83 is: 31.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.20 : 108.28 = 20.83 : x
  2. Step 2: Convert to fraction form
    72.20/108.28 = 20.83/x
  3. Step 3: Cross multiply
    72.20x = 108.28 × 20.83
  4. Step 4: Simplify right side
    72.20x = 2,255.11
  5. Step 5: Solve for x
    x = 2,255.11/72.20
  6. Step 6: Final answer
    x = 31.23

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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.