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Finding the Fourth Proportional to 258.91, 388.36 and 121.88

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Solution

The fourth proportional to 258.91, 388.36 and 121.88 is: 182.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.91 : 388.36 = 121.88 : x
  2. Step 2: Convert to fraction form
    258.91/388.36 = 121.88/x
  3. Step 3: Cross multiply
    258.91x = 388.36 × 121.88
  4. Step 4: Simplify right side
    258.91x = 47,332.04
  5. Step 5: Solve for x
    x = 47,332.04/258.91
  6. Step 6: Final answer
    x = 182.81

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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.