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Finding the Fourth Proportional to 258.32, 387.56 and 212.56

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Solution

The fourth proportional to 258.32, 387.56 and 212.56 is: 318.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.32 : 387.56 = 212.56 : x
  2. Step 2: Convert to fraction form
    258.32/387.56 = 212.56/x
  3. Step 3: Cross multiply
    258.32x = 387.56 × 212.56
  4. Step 4: Simplify right side
    258.32x = 82,379.75
  5. Step 5: Solve for x
    x = 82,379.75/258.32
  6. Step 6: Final answer
    x = 318.91

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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.