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Finding the Fourth Proportional to 821.87, 1,133.31 and 644.50

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Solution

The fourth proportional to 821.87, 1,133.31 and 644.50 is: 888.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.87 : 1,133.31 = 644.50 : x
  2. Step 2: Convert to fraction form
    821.87/1,133.31 = 644.50/x
  3. Step 3: Cross multiply
    821.87x = 1,133.31 × 644.50
  4. Step 4: Simplify right side
    821.87x = 730,418.30
  5. Step 5: Solve for x
    x = 730,418.30/821.87
  6. Step 6: Final answer
    x = 888.73

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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.