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Finding the Fourth Proportional to 729.25, 1,006.40 and 397.70

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Solution

The fourth proportional to 729.25, 1,006.40 and 397.70 is: 548.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    729.25 : 1,006.40 = 397.70 : x
  2. Step 2: Convert to fraction form
    729.25/1,006.40 = 397.70/x
  3. Step 3: Cross multiply
    729.25x = 1,006.40 × 397.70
  4. Step 4: Simplify right side
    729.25x = 400,245.28
  5. Step 5: Solve for x
    x = 400,245.28/729.25
  6. Step 6: Final answer
    x = 548.85

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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.