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Finding the Fourth Proportional to 258.89, 388.35 and 121.91

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Solution

The fourth proportional to 258.89, 388.35 and 121.91 is: 182.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.89 : 388.35 = 121.91 : x
  2. Step 2: Convert to fraction form
    258.89/388.35 = 121.91/x
  3. Step 3: Cross multiply
    258.89x = 388.35 × 121.91
  4. Step 4: Simplify right side
    258.89x = 47,341.81
  5. Step 5: Solve for x
    x = 47,341.81/258.89
  6. Step 6: Final answer
    x = 182.87

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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.