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Finding the Fourth Proportional to 74.20, 111.28 and 20.10

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Solution

The fourth proportional to 74.20, 111.28 and 20.10 is: 30.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.20 : 111.28 = 20.10 : x
  2. Step 2: Convert to fraction form
    74.20/111.28 = 20.10/x
  3. Step 3: Cross multiply
    74.20x = 111.28 × 20.10
  4. Step 4: Simplify right side
    74.20x = 2,236.73
  5. Step 5: Solve for x
    x = 2,236.73/74.20
  6. Step 6: Final answer
    x = 30.14

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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.