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Finding the Fourth Proportional to 834.80, 1,252.20 and 640.40

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Solution

The fourth proportional to 834.80, 1,252.20 and 640.40 is: 960.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    834.80 : 1,252.20 = 640.40 : x
  2. Step 2: Convert to fraction form
    834.80/1,252.20 = 640.40/x
  3. Step 3: Cross multiply
    834.80x = 1,252.20 × 640.40
  4. Step 4: Simplify right side
    834.80x = 801,908.88
  5. Step 5: Solve for x
    x = 801,908.88/834.80
  6. Step 6: Final answer
    x = 960.60

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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.