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Finding the Fourth Proportional to 1,138.38, 1,708.38 and 489.58

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Solution

The fourth proportional to 1,138.38, 1,708.38 and 489.58 is: 734.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,138.38 : 1,708.38 = 489.58 : x
  2. Step 2: Convert to fraction form
    1,138.38/1,708.38 = 489.58/x
  3. Step 3: Cross multiply
    1,138.38x = 1,708.38 × 489.58
  4. Step 4: Simplify right side
    1,138.38x = 836,388.68
  5. Step 5: Solve for x
    x = 836,388.68/1,138.38
  6. Step 6: Final answer
    x = 734.72

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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.