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Finding the Fourth Proportional to 826.52, 1,239.78 and 278.70

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Solution

The fourth proportional to 826.52, 1,239.78 and 278.70 is: 418.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.52 : 1,239.78 = 278.70 : x
  2. Step 2: Convert to fraction form
    826.52/1,239.78 = 278.70/x
  3. Step 3: Cross multiply
    826.52x = 1,239.78 × 278.70
  4. Step 4: Simplify right side
    826.52x = 345,527.70
  5. Step 5: Solve for x
    x = 345,527.70/826.52
  6. Step 6: Final answer
    x = 418.05

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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.