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Finding the Fourth Proportional to 686.42, 1,029.74 and 490.94

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Solution

The fourth proportional to 686.42, 1,029.74 and 490.94 is: 736.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.42 : 1,029.74 = 490.94 : x
  2. Step 2: Convert to fraction form
    686.42/1,029.74 = 490.94/x
  3. Step 3: Cross multiply
    686.42x = 1,029.74 × 490.94
  4. Step 4: Simplify right side
    686.42x = 505,540.56
  5. Step 5: Solve for x
    x = 505,540.56/686.42
  6. Step 6: Final answer
    x = 736.49

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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.