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Finding the Fourth Proportional to 680.39, 1,020.49 and 218.22

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Solution

The fourth proportional to 680.39, 1,020.49 and 218.22 is: 327.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.39 : 1,020.49 = 218.22 : x
  2. Step 2: Convert to fraction form
    680.39/1,020.49 = 218.22/x
  3. Step 3: Cross multiply
    680.39x = 1,020.49 × 218.22
  4. Step 4: Simplify right side
    680.39x = 222,691.33
  5. Step 5: Solve for x
    x = 222,691.33/680.39
  6. Step 6: Final answer
    x = 327.30

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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.