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Finding the Fourth Proportional to 258.49, 387.30 and 206.86

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Solution

The fourth proportional to 258.49, 387.30 and 206.86 is: 309.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.49 : 387.30 = 206.86 : x
  2. Step 2: Convert to fraction form
    258.49/387.30 = 206.86/x
  3. Step 3: Cross multiply
    258.49x = 387.30 × 206.86
  4. Step 4: Simplify right side
    258.49x = 80,116.88
  5. Step 5: Solve for x
    x = 80,116.88/258.49
  6. Step 6: Final answer
    x = 309.94

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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.