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Finding the Fourth Proportional to 789.75, 1,089.91 and 495.21

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Solution

The fourth proportional to 789.75, 1,089.91 and 495.21 is: 683.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.75 : 1,089.91 = 495.21 : x
  2. Step 2: Convert to fraction form
    789.75/1,089.91 = 495.21/x
  3. Step 3: Cross multiply
    789.75x = 1,089.91 × 495.21
  4. Step 4: Simplify right side
    789.75x = 539,736.25
  5. Step 5: Solve for x
    x = 539,736.25/789.75
  6. Step 6: Final answer
    x = 683.43

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.