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Finding the Fourth Proportional to 812.98, 1,220.16 and 326.38

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Solution

The fourth proportional to 812.98, 1,220.16 and 326.38 is: 489.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.98 : 1,220.16 = 326.38 : x
  2. Step 2: Convert to fraction form
    812.98/1,220.16 = 326.38/x
  3. Step 3: Cross multiply
    812.98x = 1,220.16 × 326.38
  4. Step 4: Simplify right side
    812.98x = 398,235.82
  5. Step 5: Solve for x
    x = 398,235.82/812.98
  6. Step 6: Final answer
    x = 489.85

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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.