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Finding the Fourth Proportional to 768.44, 1,149.72 and 643.70

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Solution

The fourth proportional to 768.44, 1,149.72 and 643.70 is: 963.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.44 : 1,149.72 = 643.70 : x
  2. Step 2: Convert to fraction form
    768.44/1,149.72 = 643.70/x
  3. Step 3: Cross multiply
    768.44x = 1,149.72 × 643.70
  4. Step 4: Simplify right side
    768.44x = 740,074.76
  5. Step 5: Solve for x
    x = 740,074.76/768.44
  6. Step 6: Final answer
    x = 963.09

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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.