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Finding the Fourth Proportional to 826.80, 1,239.88 and 339.68

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Solution

The fourth proportional to 826.80, 1,239.88 and 339.68 is: 509.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.80 : 1,239.88 = 339.68 : x
  2. Step 2: Convert to fraction form
    826.80/1,239.88 = 339.68/x
  3. Step 3: Cross multiply
    826.80x = 1,239.88 × 339.68
  4. Step 4: Simplify right side
    826.80x = 421,162.44
  5. Step 5: Solve for x
    x = 421,162.44/826.80
  6. Step 6: Final answer
    x = 509.39

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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.