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Finding the Fourth Proportional to 871.10, 1,305 and 431.84

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Solution

The fourth proportional to 871.10, 1,305 and 431.84 is: 646.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.10 : 1,305 = 431.84 : x
  2. Step 2: Convert to fraction form
    871.10/1,305 = 431.84/x
  3. Step 3: Cross multiply
    871.10x = 1,305 × 431.84
  4. Step 4: Simplify right side
    871.10x = 563,551.20
  5. Step 5: Solve for x
    x = 563,551.20/871.10
  6. Step 6: Final answer
    x = 646.94

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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.