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Finding the Fourth Proportional to 684.72, 1,025.64 and 394.80

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Solution

The fourth proportional to 684.72, 1,025.64 and 394.80 is: 591.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.72 : 1,025.64 = 394.80 : x
  2. Step 2: Convert to fraction form
    684.72/1,025.64 = 394.80/x
  3. Step 3: Cross multiply
    684.72x = 1,025.64 × 394.80
  4. Step 4: Simplify right side
    684.72x = 404,922.67
  5. Step 5: Solve for x
    x = 404,922.67/684.72
  6. Step 6: Final answer
    x = 591.37

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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.