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Finding the Fourth Proportional to 768.87, 1,153.30 and 221.05

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Solution

The fourth proportional to 768.87, 1,153.30 and 221.05 is: 331.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.87 : 1,153.30 = 221.05 : x
  2. Step 2: Convert to fraction form
    768.87/1,153.30 = 221.05/x
  3. Step 3: Cross multiply
    768.87x = 1,153.30 × 221.05
  4. Step 4: Simplify right side
    768.87x = 254,936.35
  5. Step 5: Solve for x
    x = 254,936.35/768.87
  6. Step 6: Final answer
    x = 331.57

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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.