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Finding the Fourth Proportional to 868.86, 1,305.09 and 839.70

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Solution

The fourth proportional to 868.86, 1,305.09 and 839.70 is: 1,261.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    868.86 : 1,305.09 = 839.70 : x
  2. Step 2: Convert to fraction form
    868.86/1,305.09 = 839.70/x
  3. Step 3: Cross multiply
    868.86x = 1,305.09 × 839.70
  4. Step 4: Simplify right side
    868.86x = 1,095,884.07
  5. Step 5: Solve for x
    x = 1,095,884.07/868.86
  6. Step 6: Final answer
    x = 1,261.29

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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.