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Finding the Fourth Proportional to 171.79, 257.59 and 90.61

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Solution

The fourth proportional to 171.79, 257.59 and 90.61 is: 135.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    171.79 : 257.59 = 90.61 : x
  2. Step 2: Convert to fraction form
    171.79/257.59 = 90.61/x
  3. Step 3: Cross multiply
    171.79x = 257.59 × 90.61
  4. Step 4: Simplify right side
    171.79x = 23,340.23
  5. Step 5: Solve for x
    x = 23,340.23/171.79
  6. Step 6: Final answer
    x = 135.86

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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.