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Finding the Fourth Proportional to 729.96, 1,099.31 and 639.72

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Solution

The fourth proportional to 729.96, 1,099.31 and 639.72 is: 963.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    729.96 : 1,099.31 = 639.72 : x
  2. Step 2: Convert to fraction form
    729.96/1,099.31 = 639.72/x
  3. Step 3: Cross multiply
    729.96x = 1,099.31 × 639.72
  4. Step 4: Simplify right side
    729.96x = 703,247.39
  5. Step 5: Solve for x
    x = 703,247.39/729.96
  6. Step 6: Final answer
    x = 963.41

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.