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Finding the Fourth Proportional to 40.20, 55.42 and 30.98

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Solution

The fourth proportional to 40.20, 55.42 and 30.98 is: 42.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.20 : 55.42 = 30.98 : x
  2. Step 2: Convert to fraction form
    40.20/55.42 = 30.98/x
  3. Step 3: Cross multiply
    40.20x = 55.42 × 30.98
  4. Step 4: Simplify right side
    40.20x = 1,716.91
  5. Step 5: Solve for x
    x = 1,716.91/40.20
  6. Step 6: Final answer
    x = 42.71

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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.