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Finding the Fourth Proportional to 812.82, 1,212.44 and 761.78

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Solution

The fourth proportional to 812.82, 1,212.44 and 761.78 is: 1,136.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.82 : 1,212.44 = 761.78 : x
  2. Step 2: Convert to fraction form
    812.82/1,212.44 = 761.78/x
  3. Step 3: Cross multiply
    812.82x = 1,212.44 × 761.78
  4. Step 4: Simplify right side
    812.82x = 923,612.54
  5. Step 5: Solve for x
    x = 923,612.54/812.82
  6. Step 6: Final answer
    x = 1,136.31

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.