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Finding the Fourth Proportional to 257.70, 386.18 and 171.21

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Solution

The fourth proportional to 257.70, 386.18 and 171.21 is: 256.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.70 : 386.18 = 171.21 : x
  2. Step 2: Convert to fraction form
    257.70/386.18 = 171.21/x
  3. Step 3: Cross multiply
    257.70x = 386.18 × 171.21
  4. Step 4: Simplify right side
    257.70x = 66,120.08
  5. Step 5: Solve for x
    x = 66,120.08/257.70
  6. Step 6: Final answer
    x = 256.58

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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.