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Finding the Fourth Proportional to 611.85, 917.29 and 221.79

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Solution

The fourth proportional to 611.85, 917.29 and 221.79 is: 332.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.85 : 917.29 = 221.79 : x
  2. Step 2: Convert to fraction form
    611.85/917.29 = 221.79/x
  3. Step 3: Cross multiply
    611.85x = 917.29 × 221.79
  4. Step 4: Simplify right side
    611.85x = 203,440.05
  5. Step 5: Solve for x
    x = 203,440.05/611.85
  6. Step 6: Final answer
    x = 332.50

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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.