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Finding the Fourth Proportional to 40.12, 55.36 and 21.69

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Solution

The fourth proportional to 40.12, 55.36 and 21.69 is: 29.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.12 : 55.36 = 21.69 : x
  2. Step 2: Convert to fraction form
    40.12/55.36 = 21.69/x
  3. Step 3: Cross multiply
    40.12x = 55.36 × 21.69
  4. Step 4: Simplify right side
    40.12x = 1,201.01
  5. Step 5: Solve for x
    x = 1,201.01/40.12
  6. Step 6: Final answer
    x = 29.94

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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.