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Finding the Fourth Proportional to 778.28, 1,072.90 and 757.80

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Solution

The fourth proportional to 778.28, 1,072.90 and 757.80 is: 1,044.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.28 : 1,072.90 = 757.80 : x
  2. Step 2: Convert to fraction form
    778.28/1,072.90 = 757.80/x
  3. Step 3: Cross multiply
    778.28x = 1,072.90 × 757.80
  4. Step 4: Simplify right side
    778.28x = 813,043.62
  5. Step 5: Solve for x
    x = 813,043.62/778.28
  6. Step 6: Final answer
    x = 1,044.67

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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.