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Finding the Fourth Proportional to 781.09, 1,171.11 and 342.33

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Solution

The fourth proportional to 781.09, 1,171.11 and 342.33 is: 513.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.09 : 1,171.11 = 342.33 : x
  2. Step 2: Convert to fraction form
    781.09/1,171.11 = 342.33/x
  3. Step 3: Cross multiply
    781.09x = 1,171.11 × 342.33
  4. Step 4: Simplify right side
    781.09x = 400,901.05
  5. Step 5: Solve for x
    x = 400,901.05/781.09
  6. Step 6: Final answer
    x = 513.26

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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.