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Finding the Fourth Proportional to 258.89, 388.30 and 215.83

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Solution

The fourth proportional to 258.89, 388.30 and 215.83 is: 323.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.89 : 388.30 = 215.83 : x
  2. Step 2: Convert to fraction form
    258.89/388.30 = 215.83/x
  3. Step 3: Cross multiply
    258.89x = 388.30 × 215.83
  4. Step 4: Simplify right side
    258.89x = 83,806.79
  5. Step 5: Solve for x
    x = 83,806.79/258.89
  6. Step 6: Final answer
    x = 323.72

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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.