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Finding the Fourth Proportional to 171.24, 256.78 and 139.08

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Solution

The fourth proportional to 171.24, 256.78 and 139.08 is: 208.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    171.24 : 256.78 = 139.08 : x
  2. Step 2: Convert to fraction form
    171.24/256.78 = 139.08/x
  3. Step 3: Cross multiply
    171.24x = 256.78 × 139.08
  4. Step 4: Simplify right side
    171.24x = 35,712.96
  5. Step 5: Solve for x
    x = 35,712.96/171.24
  6. Step 6: Final answer
    x = 208.56

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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.