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Finding the Fourth Proportional to 669.87, 1,006.02 and 639.09

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Solution

The fourth proportional to 669.87, 1,006.02 and 639.09 is: 959.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.87 : 1,006.02 = 639.09 : x
  2. Step 2: Convert to fraction form
    669.87/1,006.02 = 639.09/x
  3. Step 3: Cross multiply
    669.87x = 1,006.02 × 639.09
  4. Step 4: Simplify right side
    669.87x = 642,937.32
  5. Step 5: Solve for x
    x = 642,937.32/669.87
  6. Step 6: Final answer
    x = 959.79

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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.