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Finding the Fourth Proportional to 812.29, 1,218.78 and 325.21

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Solution

The fourth proportional to 812.29, 1,218.78 and 325.21 is: 487.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.29 : 1,218.78 = 325.21 : x
  2. Step 2: Convert to fraction form
    812.29/1,218.78 = 325.21/x
  3. Step 3: Cross multiply
    812.29x = 1,218.78 × 325.21
  4. Step 4: Simplify right side
    812.29x = 396,351.72
  5. Step 5: Solve for x
    x = 396,351.72/812.29
  6. Step 6: Final answer
    x = 487.95

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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.