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Finding the Fourth Proportional to 386.17, 579.29 and 142.90

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Solution

The fourth proportional to 386.17, 579.29 and 142.90 is: 214.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.17 : 579.29 = 142.90 : x
  2. Step 2: Convert to fraction form
    386.17/579.29 = 142.90/x
  3. Step 3: Cross multiply
    386.17x = 579.29 × 142.90
  4. Step 4: Simplify right side
    386.17x = 82,778.38
  5. Step 5: Solve for x
    x = 82,778.38/386.17
  6. Step 6: Final answer
    x = 214.36

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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.