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Finding the Fourth Proportional to 680.13, 938.79 and 505.71

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Solution

The fourth proportional to 680.13, 938.79 and 505.71 is: 698.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.13 : 938.79 = 505.71 : x
  2. Step 2: Convert to fraction form
    680.13/938.79 = 505.71/x
  3. Step 3: Cross multiply
    680.13x = 938.79 × 505.71
  4. Step 4: Simplify right side
    680.13x = 474,755.49
  5. Step 5: Solve for x
    x = 474,755.49/680.13
  6. Step 6: Final answer
    x = 698.04

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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.