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Finding the Fourth Proportional to 906.28, 1,249.32 and 639.85

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Solution

The fourth proportional to 906.28, 1,249.32 and 639.85 is: 882.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    906.28 : 1,249.32 = 639.85 : x
  2. Step 2: Convert to fraction form
    906.28/1,249.32 = 639.85/x
  3. Step 3: Cross multiply
    906.28x = 1,249.32 × 639.85
  4. Step 4: Simplify right side
    906.28x = 799,379.02
  5. Step 5: Solve for x
    x = 799,379.02/906.28
  6. Step 6: Final answer
    x = 882.05

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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.