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Finding the Fourth Proportional to 69.40, 104.10 and 21.30

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Solution

The fourth proportional to 69.40, 104.10 and 21.30 is: 31.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.40 : 104.10 = 21.30 : x
  2. Step 2: Convert to fraction form
    69.40/104.10 = 21.30/x
  3. Step 3: Cross multiply
    69.40x = 104.10 × 21.30
  4. Step 4: Simplify right side
    69.40x = 2,217.77
  5. Step 5: Solve for x
    x = 2,217.77/69.40
  6. Step 6: Final answer
    x = 31.96

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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.