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Finding the Fourth Proportional to 120.71, 181.08 and 91.87

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Solution

The fourth proportional to 120.71, 181.08 and 91.87 is: 137.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.71 : 181.08 = 91.87 : x
  2. Step 2: Convert to fraction form
    120.71/181.08 = 91.87/x
  3. Step 3: Cross multiply
    120.71x = 181.08 × 91.87
  4. Step 4: Simplify right side
    120.71x = 16,635.36
  5. Step 5: Solve for x
    x = 16,635.36/120.71
  6. Step 6: Final answer
    x = 137.81

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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.