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Finding the Fourth Proportional to 865.82, 1,299.40 and 379.20

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Solution

The fourth proportional to 865.82, 1,299.40 and 379.20 is: 569.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.82 : 1,299.40 = 379.20 : x
  2. Step 2: Convert to fraction form
    865.82/1,299.40 = 379.20/x
  3. Step 3: Cross multiply
    865.82x = 1,299.40 × 379.20
  4. Step 4: Simplify right side
    865.82x = 492,732.48
  5. Step 5: Solve for x
    x = 492,732.48/865.82
  6. Step 6: Final answer
    x = 569.09

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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.