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Finding the Fourth Proportional to 20.55, 30.70 and 18.43

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Solution

The fourth proportional to 20.55, 30.70 and 18.43 is: 27.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.55 : 30.70 = 18.43 : x
  2. Step 2: Convert to fraction form
    20.55/30.70 = 18.43/x
  3. Step 3: Cross multiply
    20.55x = 30.70 × 18.43
  4. Step 4: Simplify right side
    20.55x = 565.80
  5. Step 5: Solve for x
    x = 565.80/20.55
  6. Step 6: Final answer
    x = 27.53

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.