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Finding the Fourth Proportional to 768.98, 1,153.55 and 221.20

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Solution

The fourth proportional to 768.98, 1,153.55 and 221.20 is: 331.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.98 : 1,153.55 = 221.20 : x
  2. Step 2: Convert to fraction form
    768.98/1,153.55 = 221.20/x
  3. Step 3: Cross multiply
    768.98x = 1,153.55 × 221.20
  4. Step 4: Simplify right side
    768.98x = 255,162.93
  5. Step 5: Solve for x
    x = 255,162.93/768.98
  6. Step 6: Final answer
    x = 331.82

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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.