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Finding the Fourth Proportional to 812.56, 1,218.64 and 379.28

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Solution

The fourth proportional to 812.56, 1,218.64 and 379.28 is: 568.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.56 : 1,218.64 = 379.28 : x
  2. Step 2: Convert to fraction form
    812.56/1,218.64 = 379.28/x
  3. Step 3: Cross multiply
    812.56x = 1,218.64 × 379.28
  4. Step 4: Simplify right side
    812.56x = 462,205.78
  5. Step 5: Solve for x
    x = 462,205.78/812.56
  6. Step 6: Final answer
    x = 568.83

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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.