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Finding the Fourth Proportional to 685.38, 1,028.08 and 198.42

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Solution

The fourth proportional to 685.38, 1,028.08 and 198.42 is: 297.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.38 : 1,028.08 = 198.42 : x
  2. Step 2: Convert to fraction form
    685.38/1,028.08 = 198.42/x
  3. Step 3: Cross multiply
    685.38x = 1,028.08 × 198.42
  4. Step 4: Simplify right side
    685.38x = 203,991.63
  5. Step 5: Solve for x
    x = 203,991.63/685.38
  6. Step 6: Final answer
    x = 297.63

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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.