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Finding the Fourth Proportional to 37.20, 55.86 and 21.18

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Solution

The fourth proportional to 37.20, 55.86 and 21.18 is: 31.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    37.20 : 55.86 = 21.18 : x
  2. Step 2: Convert to fraction form
    37.20/55.86 = 21.18/x
  3. Step 3: Cross multiply
    37.20x = 55.86 × 21.18
  4. Step 4: Simplify right side
    37.20x = 1,183.11
  5. Step 5: Solve for x
    x = 1,183.11/37.20
  6. Step 6: Final answer
    x = 31.80

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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.