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Finding the Fourth Proportional to 40.86, 61.21 and 20.59

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Solution

The fourth proportional to 40.86, 61.21 and 20.59 is: 30.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.86 : 61.21 = 20.59 : x
  2. Step 2: Convert to fraction form
    40.86/61.21 = 20.59/x
  3. Step 3: Cross multiply
    40.86x = 61.21 × 20.59
  4. Step 4: Simplify right side
    40.86x = 1,260.07
  5. Step 5: Solve for x
    x = 1,260.07/40.86
  6. Step 6: Final answer
    x = 30.84

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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.