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Finding the Fourth Proportional to 839.34, 1,158.03 and 489.78

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Solution

The fourth proportional to 839.34, 1,158.03 and 489.78 is: 675.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.34 : 1,158.03 = 489.78 : x
  2. Step 2: Convert to fraction form
    839.34/1,158.03 = 489.78/x
  3. Step 3: Cross multiply
    839.34x = 1,158.03 × 489.78
  4. Step 4: Simplify right side
    839.34x = 567,179.93
  5. Step 5: Solve for x
    x = 567,179.93/839.34
  6. Step 6: Final answer
    x = 675.75

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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.