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Finding the Fourth Proportional to 728.18, 1,004.87 and 396.60

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Solution

The fourth proportional to 728.18, 1,004.87 and 396.60 is: 547.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.18 : 1,004.87 = 396.60 : x
  2. Step 2: Convert to fraction form
    728.18/1,004.87 = 396.60/x
  3. Step 3: Cross multiply
    728.18x = 1,004.87 × 396.60
  4. Step 4: Simplify right side
    728.18x = 398,529.46
  5. Step 5: Solve for x
    x = 398,529.46/728.18
  6. Step 6: Final answer
    x = 547.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.