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Finding the Fourth Proportional to 827.43, 1,240.78 and 388.80

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Solution

The fourth proportional to 827.43, 1,240.78 and 388.80 is: 583.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    827.43 : 1,240.78 = 388.80 : x
  2. Step 2: Convert to fraction form
    827.43/1,240.78 = 388.80/x
  3. Step 3: Cross multiply
    827.43x = 1,240.78 × 388.80
  4. Step 4: Simplify right side
    827.43x = 482,419.43
  5. Step 5: Solve for x
    x = 482,419.43/827.43
  6. Step 6: Final answer
    x = 583.03

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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.