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Finding the Fourth Proportional to 680.37, 1,020.39 and 314.79

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Solution

The fourth proportional to 680.37, 1,020.39 and 314.79 is: 472.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.37 : 1,020.39 = 314.79 : x
  2. Step 2: Convert to fraction form
    680.37/1,020.39 = 314.79/x
  3. Step 3: Cross multiply
    680.37x = 1,020.39 × 314.79
  4. Step 4: Simplify right side
    680.37x = 321,208.57
  5. Step 5: Solve for x
    x = 321,208.57/680.37
  6. Step 6: Final answer
    x = 472.11

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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.