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Finding the Fourth Proportional to 38.58, 57.81 and 20.50

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Solution

The fourth proportional to 38.58, 57.81 and 20.50 is: 30.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.58 : 57.81 = 20.50 : x
  2. Step 2: Convert to fraction form
    38.58/57.81 = 20.50/x
  3. Step 3: Cross multiply
    38.58x = 57.81 × 20.50
  4. Step 4: Simplify right side
    38.58x = 1,185.11
  5. Step 5: Solve for x
    x = 1,185.11/38.58
  6. Step 6: Final answer
    x = 30.72

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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.