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Finding the Fourth Proportional to 685.98, 1,029.20 and 320.57

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Solution

The fourth proportional to 685.98, 1,029.20 and 320.57 is: 480.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.98 : 1,029.20 = 320.57 : x
  2. Step 2: Convert to fraction form
    685.98/1,029.20 = 320.57/x
  3. Step 3: Cross multiply
    685.98x = 1,029.20 × 320.57
  4. Step 4: Simplify right side
    685.98x = 329,930.64
  5. Step 5: Solve for x
    x = 329,930.64/685.98
  6. Step 6: Final answer
    x = 480.96

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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.