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Finding the Fourth Proportional to 1,272.31, 1,908.16 and 809.39

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Solution

The fourth proportional to 1,272.31, 1,908.16 and 809.39 is: 1,213.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,272.31 : 1,908.16 = 809.39 : x
  2. Step 2: Convert to fraction form
    1,272.31/1,908.16 = 809.39/x
  3. Step 3: Cross multiply
    1,272.31x = 1,908.16 × 809.39
  4. Step 4: Simplify right side
    1,272.31x = 1,544,448.37
  5. Step 5: Solve for x
    x = 1,544,448.37/1,272.31
  6. Step 6: Final answer
    x = 1,213.90

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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.