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Finding the Fourth Proportional to 257.45, 386.17 and 172.49

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Solution

The fourth proportional to 257.45, 386.17 and 172.49 is: 258.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.45 : 386.17 = 172.49 : x
  2. Step 2: Convert to fraction form
    257.45/386.17 = 172.49/x
  3. Step 3: Cross multiply
    257.45x = 386.17 × 172.49
  4. Step 4: Simplify right side
    257.45x = 66,608.10
  5. Step 5: Solve for x
    x = 66,608.10/257.45
  6. Step 6: Final answer
    x = 258.73

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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.