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Finding the Fourth Proportional to 258.13, 387.29 and 142.43

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Solution

The fourth proportional to 258.13, 387.29 and 142.43 is: 213.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.13 : 387.29 = 142.43 : x
  2. Step 2: Convert to fraction form
    258.13/387.29 = 142.43/x
  3. Step 3: Cross multiply
    258.13x = 387.29 × 142.43
  4. Step 4: Simplify right side
    258.13x = 55,161.00
  5. Step 5: Solve for x
    x = 55,161.00/258.13
  6. Step 6: Final answer
    x = 213.69

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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.