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Finding the Fourth Proportional to 828.23, 1,240.72 and 388.90

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Solution

The fourth proportional to 828.23, 1,240.72 and 388.90 is: 582.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.23 : 1,240.72 = 388.90 : x
  2. Step 2: Convert to fraction form
    828.23/1,240.72 = 388.90/x
  3. Step 3: Cross multiply
    828.23x = 1,240.72 × 388.90
  4. Step 4: Simplify right side
    828.23x = 482,516.59
  5. Step 5: Solve for x
    x = 482,516.59/828.23
  6. Step 6: Final answer
    x = 582.59

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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.