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Finding the Fourth Proportional to 663.90, 994.30 and 640.83

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Solution

The fourth proportional to 663.90, 994.30 and 640.83 is: 959.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.90 : 994.30 = 640.83 : x
  2. Step 2: Convert to fraction form
    663.90/994.30 = 640.83/x
  3. Step 3: Cross multiply
    663.90x = 994.30 × 640.83
  4. Step 4: Simplify right side
    663.90x = 637,170.70
  5. Step 5: Solve for x
    x = 637,170.70/663.90
  6. Step 6: Final answer
    x = 959.75

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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.