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Finding the Fourth Proportional to 685.38, 1,029.28 and 654.60

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Solution

The fourth proportional to 685.38, 1,029.28 and 654.60 is: 983.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.38 : 1,029.28 = 654.60 : x
  2. Step 2: Convert to fraction form
    685.38/1,029.28 = 654.60/x
  3. Step 3: Cross multiply
    685.38x = 1,029.28 × 654.60
  4. Step 4: Simplify right side
    685.38x = 673,766.69
  5. Step 5: Solve for x
    x = 673,766.69/685.38
  6. Step 6: Final answer
    x = 983.06

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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.