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Finding the Fourth Proportional to 801.20, 1,201.80 and 769.20

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Solution

The fourth proportional to 801.20, 1,201.80 and 769.20 is: 1,153.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.20 : 1,201.80 = 769.20 : x
  2. Step 2: Convert to fraction form
    801.20/1,201.80 = 769.20/x
  3. Step 3: Cross multiply
    801.20x = 1,201.80 × 769.20
  4. Step 4: Simplify right side
    801.20x = 924,424.56
  5. Step 5: Solve for x
    x = 924,424.56/801.20
  6. Step 6: Final answer
    x = 1,153.80

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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.