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Finding the Fourth Proportional to 828.20, 1,242.78 and 308.57

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Solution

The fourth proportional to 828.20, 1,242.78 and 308.57 is: 463.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.20 : 1,242.78 = 308.57 : x
  2. Step 2: Convert to fraction form
    828.20/1,242.78 = 308.57/x
  3. Step 3: Cross multiply
    828.20x = 1,242.78 × 308.57
  4. Step 4: Simplify right side
    828.20x = 383,478.41
  5. Step 5: Solve for x
    x = 383,478.41/828.20
  6. Step 6: Final answer
    x = 463.03

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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.