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Finding the Fourth Proportional to 665.18, 996.39 and 390.44

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Solution

The fourth proportional to 665.18, 996.39 and 390.44 is: 584.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.18 : 996.39 = 390.44 : x
  2. Step 2: Convert to fraction form
    665.18/996.39 = 390.44/x
  3. Step 3: Cross multiply
    665.18x = 996.39 × 390.44
  4. Step 4: Simplify right side
    665.18x = 389,030.51
  5. Step 5: Solve for x
    x = 389,030.51/665.18
  6. Step 6: Final answer
    x = 584.85

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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.