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Finding the Fourth Proportional to 827.28, 1,239.72 and 769.80

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Solution

The fourth proportional to 827.28, 1,239.72 and 769.80 is: 1,153.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    827.28 : 1,239.72 = 769.80 : x
  2. Step 2: Convert to fraction form
    827.28/1,239.72 = 769.80/x
  3. Step 3: Cross multiply
    827.28x = 1,239.72 × 769.80
  4. Step 4: Simplify right side
    827.28x = 954,336.46
  5. Step 5: Solve for x
    x = 954,336.46/827.28
  6. Step 6: Final answer
    x = 1,153.58

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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.