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Finding the Fourth Proportional to 20.50, 30.77 and 18.71

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Solution

The fourth proportional to 20.50, 30.77 and 18.71 is: 28.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.50 : 30.77 = 18.71 : x
  2. Step 2: Convert to fraction form
    20.50/30.77 = 18.71/x
  3. Step 3: Cross multiply
    20.50x = 30.77 × 18.71
  4. Step 4: Simplify right side
    20.50x = 575.71
  5. Step 5: Solve for x
    x = 575.71/20.50
  6. Step 6: Final answer
    x = 28.08

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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.