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Finding the Fourth Proportional to 805.50, 1,205.10 and 686.88

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Solution

The fourth proportional to 805.50, 1,205.10 and 686.88 is: 1,027.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.50 : 1,205.10 = 686.88 : x
  2. Step 2: Convert to fraction form
    805.50/1,205.10 = 686.88/x
  3. Step 3: Cross multiply
    805.50x = 1,205.10 × 686.88
  4. Step 4: Simplify right side
    805.50x = 827,759.09
  5. Step 5: Solve for x
    x = 827,759.09/805.50
  6. Step 6: Final answer
    x = 1,027.63

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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.