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Finding the Fourth Proportional to 664.47, 996.44 and 390.69

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Solution

The fourth proportional to 664.47, 996.44 and 390.69 is: 585.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.47 : 996.44 = 390.69 : x
  2. Step 2: Convert to fraction form
    664.47/996.44 = 390.69/x
  3. Step 3: Cross multiply
    664.47x = 996.44 × 390.69
  4. Step 4: Simplify right side
    664.47x = 389,297.19
  5. Step 5: Solve for x
    x = 389,297.19/664.47
  6. Step 6: Final answer
    x = 585.88

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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.