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Finding the Fourth Proportional to 18.72, 27.90 and 18.15

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Solution

The fourth proportional to 18.72, 27.90 and 18.15 is: 27.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.72 : 27.90 = 18.15 : x
  2. Step 2: Convert to fraction form
    18.72/27.90 = 18.15/x
  3. Step 3: Cross multiply
    18.72x = 27.90 × 18.15
  4. Step 4: Simplify right side
    18.72x = 506.39
  5. Step 5: Solve for x
    x = 506.39/18.72
  6. Step 6: Final answer
    x = 27.05

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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.