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Finding the Fourth Proportional to 828.20, 1,242.64 and 308.43

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Solution

The fourth proportional to 828.20, 1,242.64 and 308.43 is: 462.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.20 : 1,242.64 = 308.43 : x
  2. Step 2: Convert to fraction form
    828.20/1,242.64 = 308.43/x
  3. Step 3: Cross multiply
    828.20x = 1,242.64 × 308.43
  4. Step 4: Simplify right side
    828.20x = 383,271.34
  5. Step 5: Solve for x
    x = 383,271.34/828.20
  6. Step 6: Final answer
    x = 462.78

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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.