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Finding the Fourth Proportional to 171.26, 256.85 and 79.87

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Solution

The fourth proportional to 171.26, 256.85 and 79.87 is: 119.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    171.26 : 256.85 = 79.87 : x
  2. Step 2: Convert to fraction form
    171.26/256.85 = 79.87/x
  3. Step 3: Cross multiply
    171.26x = 256.85 × 79.87
  4. Step 4: Simplify right side
    171.26x = 20,514.61
  5. Step 5: Solve for x
    x = 20,514.61/171.26
  6. Step 6: Final answer
    x = 119.78

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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.