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Finding the Fourth Proportional to 439.41, 656 and 390.81

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Solution

The fourth proportional to 439.41, 656 and 390.81 is: 583.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.41 : 656 = 390.81 : x
  2. Step 2: Convert to fraction form
    439.41/656 = 390.81/x
  3. Step 3: Cross multiply
    439.41x = 656 × 390.81
  4. Step 4: Simplify right side
    439.41x = 256,371.36
  5. Step 5: Solve for x
    x = 256,371.36/439.41
  6. Step 6: Final answer
    x = 583.44

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.