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Finding the Fourth Proportional to 20.50, 30.65 and 20.18

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Solution

The fourth proportional to 20.50, 30.65 and 20.18 is: 30.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.50 : 30.65 = 20.18 : x
  2. Step 2: Convert to fraction form
    20.50/30.65 = 20.18/x
  3. Step 3: Cross multiply
    20.50x = 30.65 × 20.18
  4. Step 4: Simplify right side
    20.50x = 618.49
  5. Step 5: Solve for x
    x = 618.49/20.50
  6. Step 6: Final answer
    x = 30.17

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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.