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Finding the Fourth Proportional to 728.21, 1,004.91 and 396.65

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Solution

The fourth proportional to 728.21, 1,004.91 and 396.65 is: 547.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.21 : 1,004.91 = 396.65 : x
  2. Step 2: Convert to fraction form
    728.21/1,004.91 = 396.65/x
  3. Step 3: Cross multiply
    728.21x = 1,004.91 × 396.65
  4. Step 4: Simplify right side
    728.21x = 398,597.55
  5. Step 5: Solve for x
    x = 398,597.55/728.21
  6. Step 6: Final answer
    x = 547.37

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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.