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Finding the Fourth Proportional to 680.40, 1,012.91 and 676.35

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Solution

The fourth proportional to 680.40, 1,012.91 and 676.35 is: 1,006.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.40 : 1,012.91 = 676.35 : x
  2. Step 2: Convert to fraction form
    680.40/1,012.91 = 676.35/x
  3. Step 3: Cross multiply
    680.40x = 1,012.91 × 676.35
  4. Step 4: Simplify right side
    680.40x = 685,078.30
  5. Step 5: Solve for x
    x = 685,078.30/680.40
  6. Step 6: Final answer
    x = 1,006.88

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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.