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Finding the Fourth Proportional to 40.71, 61.05 and 20.39

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Solution

The fourth proportional to 40.71, 61.05 and 20.39 is: 30.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.71 : 61.05 = 20.39 : x
  2. Step 2: Convert to fraction form
    40.71/61.05 = 20.39/x
  3. Step 3: Cross multiply
    40.71x = 61.05 × 20.39
  4. Step 4: Simplify right side
    40.71x = 1,244.50
  5. Step 5: Solve for x
    x = 1,244.50/40.71
  6. Step 6: Final answer
    x = 30.57

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.