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Finding the Fourth Proportional to 258.84, 388.28 and 128.97

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Solution

The fourth proportional to 258.84, 388.28 and 128.97 is: 193.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.84 : 388.28 = 128.97 : x
  2. Step 2: Convert to fraction form
    258.84/388.28 = 128.97/x
  3. Step 3: Cross multiply
    258.84x = 388.28 × 128.97
  4. Step 4: Simplify right side
    258.84x = 50,076.47
  5. Step 5: Solve for x
    x = 50,076.47/258.84
  6. Step 6: Final answer
    x = 193.46

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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.