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Finding the Fourth Proportional to 679.96, 1,020.06 and 217.78

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Solution

The fourth proportional to 679.96, 1,020.06 and 217.78 is: 326.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.96 : 1,020.06 = 217.78 : x
  2. Step 2: Convert to fraction form
    679.96/1,020.06 = 217.78/x
  3. Step 3: Cross multiply
    679.96x = 1,020.06 × 217.78
  4. Step 4: Simplify right side
    679.96x = 222,146.12
  5. Step 5: Solve for x
    x = 222,146.12/679.96
  6. Step 6: Final answer
    x = 326.70

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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.