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Finding the Fourth Proportional to 386.38, 579.69 and 142.91

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Solution

The fourth proportional to 386.38, 579.69 and 142.91 is: 214.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.38 : 579.69 = 142.91 : x
  2. Step 2: Convert to fraction form
    386.38/579.69 = 142.91/x
  3. Step 3: Cross multiply
    386.38x = 579.69 × 142.91
  4. Step 4: Simplify right side
    386.38x = 82,843.50
  5. Step 5: Solve for x
    x = 82,843.50/386.38
  6. Step 6: Final answer
    x = 214.41

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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.