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Finding the Fourth Proportional to 258.28, 387.16 and 142.62

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Solution

The fourth proportional to 258.28, 387.16 and 142.62 is: 213.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.28 : 387.16 = 142.62 : x
  2. Step 2: Convert to fraction form
    258.28/387.16 = 142.62/x
  3. Step 3: Cross multiply
    258.28x = 387.16 × 142.62
  4. Step 4: Simplify right side
    258.28x = 55,216.76
  5. Step 5: Solve for x
    x = 55,216.76/258.28
  6. Step 6: Final answer
    x = 213.79

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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.