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Finding the Fourth Proportional to 685.41, 1,028.30 and 198.47

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Solution

The fourth proportional to 685.41, 1,028.30 and 198.47 is: 297.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.41 : 1,028.30 = 198.47 : x
  2. Step 2: Convert to fraction form
    685.41/1,028.30 = 198.47/x
  3. Step 3: Cross multiply
    685.41x = 1,028.30 × 198.47
  4. Step 4: Simplify right side
    685.41x = 204,080.57
  5. Step 5: Solve for x
    x = 204,080.57/685.41
  6. Step 6: Final answer
    x = 297.75

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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.