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Finding the Fourth Proportional to 119.91, 180.49 and 85.91

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Solution

The fourth proportional to 119.91, 180.49 and 85.91 is: 129.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    119.91 : 180.49 = 85.91 : x
  2. Step 2: Convert to fraction form
    119.91/180.49 = 85.91/x
  3. Step 3: Cross multiply
    119.91x = 180.49 × 85.91
  4. Step 4: Simplify right side
    119.91x = 15,504.99
  5. Step 5: Solve for x
    x = 15,504.99/119.91
  6. Step 6: Final answer
    x = 129.31

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.