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Finding the Fourth Proportional to 258.17, 387.11 and 171.20

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Solution

The fourth proportional to 258.17, 387.11 and 171.20 is: 256.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.17 : 387.11 = 171.20 : x
  2. Step 2: Convert to fraction form
    258.17/387.11 = 171.20/x
  3. Step 3: Cross multiply
    258.17x = 387.11 × 171.20
  4. Step 4: Simplify right side
    258.17x = 66,270.44
  5. Step 5: Solve for x
    x = 66,270.44/258.17
  6. Step 6: Final answer
    x = 256.70

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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.