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Finding the Fourth Proportional to 40.38, 55.78 and 31.66

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Solution

The fourth proportional to 40.38, 55.78 and 31.66 is: 43.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.38 : 55.78 = 31.66 : x
  2. Step 2: Convert to fraction form
    40.38/55.78 = 31.66/x
  3. Step 3: Cross multiply
    40.38x = 55.78 × 31.66
  4. Step 4: Simplify right side
    40.38x = 1,765.99
  5. Step 5: Solve for x
    x = 1,765.99/40.38
  6. Step 6: Final answer
    x = 43.73

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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.