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Finding the Fourth Proportional to 20.70, 28.32 and 20.61

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Solution

The fourth proportional to 20.70, 28.32 and 20.61 is: 28.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.70 : 28.32 = 20.61 : x
  2. Step 2: Convert to fraction form
    20.70/28.32 = 20.61/x
  3. Step 3: Cross multiply
    20.70x = 28.32 × 20.61
  4. Step 4: Simplify right side
    20.70x = 583.68
  5. Step 5: Solve for x
    x = 583.68/20.70
  6. Step 6: Final answer
    x = 28.20

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.