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Finding the Fourth Proportional to 871.31, 1,305.10 and 809.34

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Solution

The fourth proportional to 871.31, 1,305.10 and 809.34 is: 1,212.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.31 : 1,305.10 = 809.34 : x
  2. Step 2: Convert to fraction form
    871.31/1,305.10 = 809.34/x
  3. Step 3: Cross multiply
    871.31x = 1,305.10 × 809.34
  4. Step 4: Simplify right side
    871.31x = 1,056,269.63
  5. Step 5: Solve for x
    x = 1,056,269.63/871.31
  6. Step 6: Final answer
    x = 1,212.28

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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.