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Finding the Fourth Proportional to 80.51, 120.77 and 39.92

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Solution

The fourth proportional to 80.51, 120.77 and 39.92 is: 59.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.51 : 120.77 = 39.92 : x
  2. Step 2: Convert to fraction form
    80.51/120.77 = 39.92/x
  3. Step 3: Cross multiply
    80.51x = 120.77 × 39.92
  4. Step 4: Simplify right side
    80.51x = 4,820.33
  5. Step 5: Solve for x
    x = 4,820.33/80.51
  6. Step 6: Final answer
    x = 59.88

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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.