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Finding the Fourth Proportional to 812.97, 1,119.42 and 720.09

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Solution

The fourth proportional to 812.97, 1,119.42 and 720.09 is: 991.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.97 : 1,119.42 = 720.09 : x
  2. Step 2: Convert to fraction form
    812.97/1,119.42 = 720.09/x
  3. Step 3: Cross multiply
    812.97x = 1,119.42 × 720.09
  4. Step 4: Simplify right side
    812.97x = 806,083.15
  5. Step 5: Solve for x
    x = 806,083.15/812.97
  6. Step 6: Final answer
    x = 991.53

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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.