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Finding the Fourth Proportional to 286.56, 430.20 and 142.20

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Solution

The fourth proportional to 286.56, 430.20 and 142.20 is: 213.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.56 : 430.20 = 142.20 : x
  2. Step 2: Convert to fraction form
    286.56/430.20 = 142.20/x
  3. Step 3: Cross multiply
    286.56x = 430.20 × 142.20
  4. Step 4: Simplify right side
    286.56x = 61,174.44
  5. Step 5: Solve for x
    x = 61,174.44/286.56
  6. Step 6: Final answer
    x = 213.48

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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.