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Finding the Fourth Proportional to 928.90, 1,391.73 and 489.49

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Solution

The fourth proportional to 928.90, 1,391.73 and 489.49 is: 733.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.90 : 1,391.73 = 489.49 : x
  2. Step 2: Convert to fraction form
    928.90/1,391.73 = 489.49/x
  3. Step 3: Cross multiply
    928.90x = 1,391.73 × 489.49
  4. Step 4: Simplify right side
    928.90x = 681,237.92
  5. Step 5: Solve for x
    x = 681,237.92/928.90
  6. Step 6: Final answer
    x = 733.38

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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.