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Finding the Fourth Proportional to 478.25, 660.31 and 321.12

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Solution

The fourth proportional to 478.25, 660.31 and 321.12 is: 443.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.25 : 660.31 = 321.12 : x
  2. Step 2: Convert to fraction form
    478.25/660.31 = 321.12/x
  3. Step 3: Cross multiply
    478.25x = 660.31 × 321.12
  4. Step 4: Simplify right side
    478.25x = 212,033.84
  5. Step 5: Solve for x
    x = 212,033.84/478.25
  6. Step 6: Final answer
    x = 443.36

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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.