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Finding the Fourth Proportional to 768.90, 1,147.07 and 660.90

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Solution

The fourth proportional to 768.90, 1,147.07 and 660.90 is: 985.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.90 : 1,147.07 = 660.90 : x
  2. Step 2: Convert to fraction form
    768.90/1,147.07 = 660.90/x
  3. Step 3: Cross multiply
    768.90x = 1,147.07 × 660.90
  4. Step 4: Simplify right side
    768.90x = 758,095.26
  5. Step 5: Solve for x
    x = 758,095.26/768.90
  6. Step 6: Final answer
    x = 985.95

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.