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Finding the Fourth Proportional to 905.05, 1,248.99 and 639.96

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Solution

The fourth proportional to 905.05, 1,248.99 and 639.96 is: 883.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.05 : 1,248.99 = 639.96 : x
  2. Step 2: Convert to fraction form
    905.05/1,248.99 = 639.96/x
  3. Step 3: Cross multiply
    905.05x = 1,248.99 × 639.96
  4. Step 4: Simplify right side
    905.05x = 799,310.74
  5. Step 5: Solve for x
    x = 799,310.74/905.05
  6. Step 6: Final answer
    x = 883.17

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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.