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Finding the Fourth Proportional to 685.69, 1,027.71 and 393.39

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Solution

The fourth proportional to 685.69, 1,027.71 and 393.39 is: 589.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.69 : 1,027.71 = 393.39 : x
  2. Step 2: Convert to fraction form
    685.69/1,027.71 = 393.39/x
  3. Step 3: Cross multiply
    685.69x = 1,027.71 × 393.39
  4. Step 4: Simplify right side
    685.69x = 404,290.84
  5. Step 5: Solve for x
    x = 404,290.84/685.69
  6. Step 6: Final answer
    x = 589.61

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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.