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Finding the Fourth Proportional to 112.08, 154.80 and 99.78

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Solution

The fourth proportional to 112.08, 154.80 and 99.78 is: 137.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.08 : 154.80 = 99.78 : x
  2. Step 2: Convert to fraction form
    112.08/154.80 = 99.78/x
  3. Step 3: Cross multiply
    112.08x = 154.80 × 99.78
  4. Step 4: Simplify right side
    112.08x = 15,446.09
  5. Step 5: Solve for x
    x = 15,446.09/112.08
  6. Step 6: Final answer
    x = 137.81

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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.