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Finding the Fourth Proportional to 171.87, 257.88 and 90.68

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Solution

The fourth proportional to 171.87, 257.88 and 90.68 is: 136.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    171.87 : 257.88 = 90.68 : x
  2. Step 2: Convert to fraction form
    171.87/257.88 = 90.68/x
  3. Step 3: Cross multiply
    171.87x = 257.88 × 90.68
  4. Step 4: Simplify right side
    171.87x = 23,383.27
  5. Step 5: Solve for x
    x = 23,383.27/171.87
  6. Step 6: Final answer
    x = 136.05

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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.