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Finding the Fourth Proportional to 258.28, 387.20 and 161.88

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Solution

The fourth proportional to 258.28, 387.20 and 161.88 is: 242.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.28 : 387.20 = 161.88 : x
  2. Step 2: Convert to fraction form
    258.28/387.20 = 161.88/x
  3. Step 3: Cross multiply
    258.28x = 387.20 × 161.88
  4. Step 4: Simplify right side
    258.28x = 62,679.94
  5. Step 5: Solve for x
    x = 62,679.94/258.28
  6. Step 6: Final answer
    x = 242.68

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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.