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Finding the Fourth Proportional to 862.09, 1,189.68 and 489.07

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Solution

The fourth proportional to 862.09, 1,189.68 and 489.07 is: 674.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.09 : 1,189.68 = 489.07 : x
  2. Step 2: Convert to fraction form
    862.09/1,189.68 = 489.07/x
  3. Step 3: Cross multiply
    862.09x = 1,189.68 × 489.07
  4. Step 4: Simplify right side
    862.09x = 581,836.80
  5. Step 5: Solve for x
    x = 581,836.80/862.09
  6. Step 6: Final answer
    x = 674.91

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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.