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Finding the Fourth Proportional to 769.28, 1,153.10 and 728.78

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Solution

The fourth proportional to 769.28, 1,153.10 and 728.78 is: 1,092.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    769.28 : 1,153.10 = 728.78 : x
  2. Step 2: Convert to fraction form
    769.28/1,153.10 = 728.78/x
  3. Step 3: Cross multiply
    769.28x = 1,153.10 × 728.78
  4. Step 4: Simplify right side
    769.28x = 840,356.22
  5. Step 5: Solve for x
    x = 840,356.22/769.28
  6. Step 6: Final answer
    x = 1,092.39

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.