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Finding the Fourth Proportional to 663.20, 993.72 and 389.52

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Solution

The fourth proportional to 663.20, 993.72 and 389.52 is: 583.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.20 : 993.72 = 389.52 : x
  2. Step 2: Convert to fraction form
    663.20/993.72 = 389.52/x
  3. Step 3: Cross multiply
    663.20x = 993.72 × 389.52
  4. Step 4: Simplify right side
    663.20x = 387,073.81
  5. Step 5: Solve for x
    x = 387,073.81/663.20
  6. Step 6: Final answer
    x = 583.65

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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.