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Finding the Fourth Proportional to 20.15, 30.10 and 18.98

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Solution

The fourth proportional to 20.15, 30.10 and 18.98 is: 28.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.15 : 30.10 = 18.98 : x
  2. Step 2: Convert to fraction form
    20.15/30.10 = 18.98/x
  3. Step 3: Cross multiply
    20.15x = 30.10 × 18.98
  4. Step 4: Simplify right side
    20.15x = 571.40
  5. Step 5: Solve for x
    x = 571.40/20.15
  6. Step 6: Final answer
    x = 28.35

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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.