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Finding the Fourth Proportional to 112.79, 169.19 and 51.90

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Solution

The fourth proportional to 112.79, 169.19 and 51.90 is: 77.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.79 : 169.19 = 51.90 : x
  2. Step 2: Convert to fraction form
    112.79/169.19 = 51.90/x
  3. Step 3: Cross multiply
    112.79x = 169.19 × 51.90
  4. Step 4: Simplify right side
    112.79x = 8,780.70
  5. Step 5: Solve for x
    x = 8,780.70/112.79
  6. Step 6: Final answer
    x = 77.85

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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.