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Finding the Fourth Proportional to 685.42, 1,028.09 and 198.41

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Solution

The fourth proportional to 685.42, 1,028.09 and 198.41 is: 297.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.42 : 1,028.09 = 198.41 : x
  2. Step 2: Convert to fraction form
    685.42/1,028.09 = 198.41/x
  3. Step 3: Cross multiply
    685.42x = 1,028.09 × 198.41
  4. Step 4: Simplify right side
    685.42x = 203,978.69
  5. Step 5: Solve for x
    x = 203,978.69/685.42
  6. Step 6: Final answer
    x = 297.60

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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.