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Finding the Fourth Proportional to 862.21, 1,189.77 and 489.07

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Solution

The fourth proportional to 862.21, 1,189.77 and 489.07 is: 674.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.21 : 1,189.77 = 489.07 : x
  2. Step 2: Convert to fraction form
    862.21/1,189.77 = 489.07/x
  3. Step 3: Cross multiply
    862.21x = 1,189.77 × 489.07
  4. Step 4: Simplify right side
    862.21x = 581,874.87
  5. Step 5: Solve for x
    x = 581,874.87/862.21
  6. Step 6: Final answer
    x = 674.87

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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.