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Finding the Fourth Proportional to 685.71, 1,028.43 and 198.63

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Solution

The fourth proportional to 685.71, 1,028.43 and 198.63 is: 297.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.71 : 1,028.43 = 198.63 : x
  2. Step 2: Convert to fraction form
    685.71/1,028.43 = 198.63/x
  3. Step 3: Cross multiply
    685.71x = 1,028.43 × 198.63
  4. Step 4: Simplify right side
    685.71x = 204,277.05
  5. Step 5: Solve for x
    x = 204,277.05/685.71
  6. Step 6: Final answer
    x = 297.91

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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.