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Finding the Fourth Proportional to 8.21, 12.31 and 3.70

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Solution

The fourth proportional to 8.21, 12.31 and 3.70 is: 5.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.21 : 12.31 = 3.70 : x
  2. Step 2: Convert to fraction form
    8.21/12.31 = 3.70/x
  3. Step 3: Cross multiply
    8.21x = 12.31 × 3.70
  4. Step 4: Simplify right side
    8.21x = 45.55
  5. Step 5: Solve for x
    x = 45.55/8.21
  6. Step 6: Final answer
    x = 5.55

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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.