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Finding the Fourth Proportional to 220.88, 328.98 and 209.31

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Solution

The fourth proportional to 220.88, 328.98 and 209.31 is: 311.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.88 : 328.98 = 209.31 : x
  2. Step 2: Convert to fraction form
    220.88/328.98 = 209.31/x
  3. Step 3: Cross multiply
    220.88x = 328.98 × 209.31
  4. Step 4: Simplify right side
    220.88x = 68,858.80
  5. Step 5: Solve for x
    x = 68,858.80/220.88
  6. Step 6: Final answer
    x = 311.75

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.