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Finding the Fourth Proportional to 171.85, 257.75 and 79.28

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Solution

The fourth proportional to 171.85, 257.75 and 79.28 is: 118.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    171.85 : 257.75 = 79.28 : x
  2. Step 2: Convert to fraction form
    171.85/257.75 = 79.28/x
  3. Step 3: Cross multiply
    171.85x = 257.75 × 79.28
  4. Step 4: Simplify right side
    171.85x = 20,433.13
  5. Step 5: Solve for x
    x = 20,433.13/171.85
  6. Step 6: Final answer
    x = 118.90

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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.