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Finding the Fourth Proportional to 809.29, 1,115.97 and 640.97

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Solution

The fourth proportional to 809.29, 1,115.97 and 640.97 is: 883.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.29 : 1,115.97 = 640.97 : x
  2. Step 2: Convert to fraction form
    809.29/1,115.97 = 640.97/x
  3. Step 3: Cross multiply
    809.29x = 1,115.97 × 640.97
  4. Step 4: Simplify right side
    809.29x = 715,303.29
  5. Step 5: Solve for x
    x = 715,303.29/809.29
  6. Step 6: Final answer
    x = 883.87

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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.