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Finding the Fourth Proportional to 871.38, 1,305.72 and 688.32

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Solution

The fourth proportional to 871.38, 1,305.72 and 688.32 is: 1,031.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.38 : 1,305.72 = 688.32 : x
  2. Step 2: Convert to fraction form
    871.38/1,305.72 = 688.32/x
  3. Step 3: Cross multiply
    871.38x = 1,305.72 × 688.32
  4. Step 4: Simplify right side
    871.38x = 898,753.19
  5. Step 5: Solve for x
    x = 898,753.19/871.38
  6. Step 6: Final answer
    x = 1,031.41

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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.