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Finding the Fourth Proportional to 768.85, 1,153.47 and 221.07

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Solution

The fourth proportional to 768.85, 1,153.47 and 221.07 is: 331.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.85 : 1,153.47 = 221.07 : x
  2. Step 2: Convert to fraction form
    768.85/1,153.47 = 221.07/x
  3. Step 3: Cross multiply
    768.85x = 1,153.47 × 221.07
  4. Step 4: Simplify right side
    768.85x = 254,997.61
  5. Step 5: Solve for x
    x = 254,997.61/768.85
  6. Step 6: Final answer
    x = 331.66

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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.