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Finding the Fourth Proportional to 49.40, 74.09 and 20.12

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Solution

The fourth proportional to 49.40, 74.09 and 20.12 is: 30.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    49.40 : 74.09 = 20.12 : x
  2. Step 2: Convert to fraction form
    49.40/74.09 = 20.12/x
  3. Step 3: Cross multiply
    49.40x = 74.09 × 20.12
  4. Step 4: Simplify right side
    49.40x = 1,490.94
  5. Step 5: Solve for x
    x = 1,490.94/49.40
  6. Step 6: Final answer
    x = 30.18

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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.