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Finding the Fourth Proportional to 680.11, 938.72 and 505.15

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Solution

The fourth proportional to 680.11, 938.72 and 505.15 is: 697.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.11 : 938.72 = 505.15 : x
  2. Step 2: Convert to fraction form
    680.11/938.72 = 505.15/x
  3. Step 3: Cross multiply
    680.11x = 938.72 × 505.15
  4. Step 4: Simplify right side
    680.11x = 474,194.41
  5. Step 5: Solve for x
    x = 474,194.41/680.11
  6. Step 6: Final answer
    x = 697.23

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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.