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Finding the Fourth Proportional to 660.39, 990.05 and 443.85

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Solution

The fourth proportional to 660.39, 990.05 and 443.85 is: 665.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.39 : 990.05 = 443.85 : x
  2. Step 2: Convert to fraction form
    660.39/990.05 = 443.85/x
  3. Step 3: Cross multiply
    660.39x = 990.05 × 443.85
  4. Step 4: Simplify right side
    660.39x = 439,431.47
  5. Step 5: Solve for x
    x = 439,431.47/660.39
  6. Step 6: Final answer
    x = 665.41

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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.