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Finding the Fourth Proportional to 1,318.38, 1,819.32 and 728.91

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Solution

The fourth proportional to 1,318.38, 1,819.32 and 728.91 is: 1,005.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,318.38 : 1,819.32 = 728.91 : x
  2. Step 2: Convert to fraction form
    1,318.38/1,819.32 = 728.91/x
  3. Step 3: Cross multiply
    1,318.38x = 1,819.32 × 728.91
  4. Step 4: Simplify right side
    1,318.38x = 1,326,120.54
  5. Step 5: Solve for x
    x = 1,326,120.54/1,318.38
  6. Step 6: Final answer
    x = 1,005.87

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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.