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Finding the Fourth Proportional to 258.45, 387.21 and 231.12

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Solution

The fourth proportional to 258.45, 387.21 and 231.12 is: 346.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.45 : 387.21 = 231.12 : x
  2. Step 2: Convert to fraction form
    258.45/387.21 = 231.12/x
  3. Step 3: Cross multiply
    258.45x = 387.21 × 231.12
  4. Step 4: Simplify right side
    258.45x = 89,491.98
  5. Step 5: Solve for x
    x = 89,491.98/258.45
  6. Step 6: Final answer
    x = 346.26

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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.