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Finding the Fourth Proportional to 686.24, 1,022.84 and 663.74

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Solution

The fourth proportional to 686.24, 1,022.84 and 663.74 is: 989.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.24 : 1,022.84 = 663.74 : x
  2. Step 2: Convert to fraction form
    686.24/1,022.84 = 663.74/x
  3. Step 3: Cross multiply
    686.24x = 1,022.84 × 663.74
  4. Step 4: Simplify right side
    686.24x = 678,899.82
  5. Step 5: Solve for x
    x = 678,899.82/686.24
  6. Step 6: Final answer
    x = 989.30

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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.