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Finding the Fourth Proportional to 213.45, 320.11 and 69.15

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Solution

The fourth proportional to 213.45, 320.11 and 69.15 is: 103.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.45 : 320.11 = 69.15 : x
  2. Step 2: Convert to fraction form
    213.45/320.11 = 69.15/x
  3. Step 3: Cross multiply
    213.45x = 320.11 × 69.15
  4. Step 4: Simplify right side
    213.45x = 22,135.61
  5. Step 5: Solve for x
    x = 22,135.61/213.45
  6. Step 6: Final answer
    x = 103.70

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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.