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Finding the Fourth Proportional to 826.20, 1,239.39 and 339.18

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Solution

The fourth proportional to 826.20, 1,239.39 and 339.18 is: 508.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.20 : 1,239.39 = 339.18 : x
  2. Step 2: Convert to fraction form
    826.20/1,239.39 = 339.18/x
  3. Step 3: Cross multiply
    826.20x = 1,239.39 × 339.18
  4. Step 4: Simplify right side
    826.20x = 420,376.30
  5. Step 5: Solve for x
    x = 420,376.30/826.20
  6. Step 6: Final answer
    x = 508.81

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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.