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Finding the Fourth Proportional to 39.81, 59.66 and 20.54

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Solution

The fourth proportional to 39.81, 59.66 and 20.54 is: 30.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.81 : 59.66 = 20.54 : x
  2. Step 2: Convert to fraction form
    39.81/59.66 = 20.54/x
  3. Step 3: Cross multiply
    39.81x = 59.66 × 20.54
  4. Step 4: Simplify right side
    39.81x = 1,225.02
  5. Step 5: Solve for x
    x = 1,225.02/39.81
  6. Step 6: Final answer
    x = 30.77

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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.