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Finding the Fourth Proportional to 679.31, 1,018.84 and 217.11

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Solution

The fourth proportional to 679.31, 1,018.84 and 217.11 is: 325.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.31 : 1,018.84 = 217.11 : x
  2. Step 2: Convert to fraction form
    679.31/1,018.84 = 217.11/x
  3. Step 3: Cross multiply
    679.31x = 1,018.84 × 217.11
  4. Step 4: Simplify right side
    679.31x = 221,200.35
  5. Step 5: Solve for x
    x = 221,200.35/679.31
  6. Step 6: Final answer
    x = 325.63

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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.