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Finding the Fourth Proportional to 120.31, 180.51 and 51.91

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Solution

The fourth proportional to 120.31, 180.51 and 51.91 is: 77.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.31 : 180.51 = 51.91 : x
  2. Step 2: Convert to fraction form
    120.31/180.51 = 51.91/x
  3. Step 3: Cross multiply
    120.31x = 180.51 × 51.91
  4. Step 4: Simplify right side
    120.31x = 9,370.27
  5. Step 5: Solve for x
    x = 9,370.27/120.31
  6. Step 6: Final answer
    x = 77.88

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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.