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Finding the Fourth Proportional to 478.48, 660.18 and 321.40

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Solution

The fourth proportional to 478.48, 660.18 and 321.40 is: 443.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.48 : 660.18 = 321.40 : x
  2. Step 2: Convert to fraction form
    478.48/660.18 = 321.40/x
  3. Step 3: Cross multiply
    478.48x = 660.18 × 321.40
  4. Step 4: Simplify right side
    478.48x = 212,183.88
  5. Step 5: Solve for x
    x = 212,183.88/478.48
  6. Step 6: Final answer
    x = 443.45

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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.