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Finding the Fourth Proportional to 611.39, 917.09 and 221.30

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Solution

The fourth proportional to 611.39, 917.09 and 221.30 is: 331.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.39 : 917.09 = 221.30 : x
  2. Step 2: Convert to fraction form
    611.39/917.09 = 221.30/x
  3. Step 3: Cross multiply
    611.39x = 917.09 × 221.30
  4. Step 4: Simplify right side
    611.39x = 202,949.76
  5. Step 5: Solve for x
    x = 202,949.76/611.39
  6. Step 6: Final answer
    x = 331.95

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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.