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Finding the Fourth Proportional to 258.54, 387.88 and 136.90

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Solution

The fourth proportional to 258.54, 387.88 and 136.90 is: 205.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.54 : 387.88 = 136.90 : x
  2. Step 2: Convert to fraction form
    258.54/387.88 = 136.90/x
  3. Step 3: Cross multiply
    258.54x = 387.88 × 136.90
  4. Step 4: Simplify right side
    258.54x = 53,100.77
  5. Step 5: Solve for x
    x = 53,100.77/258.54
  6. Step 6: Final answer
    x = 205.39

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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.