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Finding the Fourth Proportional to 679.88, 1,019.89 and 217.55

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Solution

The fourth proportional to 679.88, 1,019.89 and 217.55 is: 326.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.88 : 1,019.89 = 217.55 : x
  2. Step 2: Convert to fraction form
    679.88/1,019.89 = 217.55/x
  3. Step 3: Cross multiply
    679.88x = 1,019.89 × 217.55
  4. Step 4: Simplify right side
    679.88x = 221,872.93
  5. Step 5: Solve for x
    x = 221,872.93/679.88
  6. Step 6: Final answer
    x = 326.34

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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.