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Finding the Fourth Proportional to 828.53, 1,247.72 and 721.61

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Solution

The fourth proportional to 828.53, 1,247.72 and 721.61 is: 1,086.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.53 : 1,247.72 = 721.61 : x
  2. Step 2: Convert to fraction form
    828.53/1,247.72 = 721.61/x
  3. Step 3: Cross multiply
    828.53x = 1,247.72 × 721.61
  4. Step 4: Simplify right side
    828.53x = 900,366.36
  5. Step 5: Solve for x
    x = 900,366.36/828.53
  6. Step 6: Final answer
    x = 1,086.71

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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.