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Finding the Fourth Proportional to 258.61, 387.46 and 215.56

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Solution

The fourth proportional to 258.61, 387.46 and 215.56 is: 322.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.61 : 387.46 = 215.56 : x
  2. Step 2: Convert to fraction form
    258.61/387.46 = 215.56/x
  3. Step 3: Cross multiply
    258.61x = 387.46 × 215.56
  4. Step 4: Simplify right side
    258.61x = 83,520.88
  5. Step 5: Solve for x
    x = 83,520.88/258.61
  6. Step 6: Final answer
    x = 322.96

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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.