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Finding the Fourth Proportional to 321.84, 442.92 and 285.12

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Solution

The fourth proportional to 321.84, 442.92 and 285.12 is: 392.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.84 : 442.92 = 285.12 : x
  2. Step 2: Convert to fraction form
    321.84/442.92 = 285.12/x
  3. Step 3: Cross multiply
    321.84x = 442.92 × 285.12
  4. Step 4: Simplify right side
    321.84x = 126,285.35
  5. Step 5: Solve for x
    x = 126,285.35/321.84
  6. Step 6: Final answer
    x = 392.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.