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Finding the Fourth Proportional to 112.20, 155.03 and 99.81

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Solution

The fourth proportional to 112.20, 155.03 and 99.81 is: 137.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.20 : 155.03 = 99.81 : x
  2. Step 2: Convert to fraction form
    112.20/155.03 = 99.81/x
  3. Step 3: Cross multiply
    112.20x = 155.03 × 99.81
  4. Step 4: Simplify right side
    112.20x = 15,473.05
  5. Step 5: Solve for x
    x = 15,473.05/112.20
  6. Step 6: Final answer
    x = 137.91

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.