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Finding the Fourth Proportional to 1,287.66, 1,776.67 and 868.79

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Solution

The fourth proportional to 1,287.66, 1,776.67 and 868.79 is: 1,198.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.66 : 1,776.67 = 868.79 : x
  2. Step 2: Convert to fraction form
    1,287.66/1,776.67 = 868.79/x
  3. Step 3: Cross multiply
    1,287.66x = 1,776.67 × 868.79
  4. Step 4: Simplify right side
    1,287.66x = 1,543,553.62
  5. Step 5: Solve for x
    x = 1,543,553.62/1,287.66
  6. Step 6: Final answer
    x = 1,198.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.