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Finding the Fourth Proportional to 59.21, 81.69 and 39.80

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Solution

The fourth proportional to 59.21, 81.69 and 39.80 is: 54.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    59.21 : 81.69 = 39.80 : x
  2. Step 2: Convert to fraction form
    59.21/81.69 = 39.80/x
  3. Step 3: Cross multiply
    59.21x = 81.69 × 39.80
  4. Step 4: Simplify right side
    59.21x = 3,250.85
  5. Step 5: Solve for x
    x = 3,250.85/59.21
  6. Step 6: Final answer
    x = 54.91

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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.