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Finding the Fourth Proportional to 22.70, 31.29 and 20.72

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Solution

The fourth proportional to 22.70, 31.29 and 20.72 is: 28.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.70 : 31.29 = 20.72 : x
  2. Step 2: Convert to fraction form
    22.70/31.29 = 20.72/x
  3. Step 3: Cross multiply
    22.70x = 31.29 × 20.72
  4. Step 4: Simplify right side
    22.70x = 648.33
  5. Step 5: Solve for x
    x = 648.33/22.70
  6. Step 6: Final answer
    x = 28.56

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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.