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Finding the Fourth Proportional to 40.81, 61.20 and 39.05

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Solution

The fourth proportional to 40.81, 61.20 and 39.05 is: 58.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.81 : 61.20 = 39.05 : x
  2. Step 2: Convert to fraction form
    40.81/61.20 = 39.05/x
  3. Step 3: Cross multiply
    40.81x = 61.20 × 39.05
  4. Step 4: Simplify right side
    40.81x = 2,389.86
  5. Step 5: Solve for x
    x = 2,389.86/40.81
  6. Step 6: Final answer
    x = 58.56

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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.