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Finding the Fourth Proportional to 722.20, 994.02 and 639.64

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Solution

The fourth proportional to 722.20, 994.02 and 639.64 is: 880.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    722.20 : 994.02 = 639.64 : x
  2. Step 2: Convert to fraction form
    722.20/994.02 = 639.64/x
  3. Step 3: Cross multiply
    722.20x = 994.02 × 639.64
  4. Step 4: Simplify right side
    722.20x = 635,814.95
  5. Step 5: Solve for x
    x = 635,814.95/722.20
  6. Step 6: Final answer
    x = 880.39

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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.