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Finding the Fourth Proportional to 1,286.07, 1,929.08 and 408.65

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Solution

The fourth proportional to 1,286.07, 1,929.08 and 408.65 is: 612.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.07 : 1,929.08 = 408.65 : x
  2. Step 2: Convert to fraction form
    1,286.07/1,929.08 = 408.65/x
  3. Step 3: Cross multiply
    1,286.07x = 1,929.08 × 408.65
  4. Step 4: Simplify right side
    1,286.07x = 788,318.54
  5. Step 5: Solve for x
    x = 788,318.54/1,286.07
  6. Step 6: Final answer
    x = 612.97

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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.