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Finding the Fourth Proportional to 112.76, 168.84 and 89.78

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Solution

The fourth proportional to 112.76, 168.84 and 89.78 is: 134.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.76 : 168.84 = 89.78 : x
  2. Step 2: Convert to fraction form
    112.76/168.84 = 89.78/x
  3. Step 3: Cross multiply
    112.76x = 168.84 × 89.78
  4. Step 4: Simplify right side
    112.76x = 15,158.46
  5. Step 5: Solve for x
    x = 15,158.46/112.76
  6. Step 6: Final answer
    x = 134.43

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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.