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Finding the Fourth Proportional to 80.15, 120.21 and 39.59

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Solution

The fourth proportional to 80.15, 120.21 and 39.59 is: 59.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.15 : 120.21 = 39.59 : x
  2. Step 2: Convert to fraction form
    80.15/120.21 = 39.59/x
  3. Step 3: Cross multiply
    80.15x = 120.21 × 39.59
  4. Step 4: Simplify right side
    80.15x = 4,759.41
  5. Step 5: Solve for x
    x = 4,759.41/80.15
  6. Step 6: Final answer
    x = 59.39

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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.