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Finding the Fourth Proportional to 28.15, 42.17 and 18.53

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Solution

The fourth proportional to 28.15, 42.17 and 18.53 is: 27.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.15 : 42.17 = 18.53 : x
  2. Step 2: Convert to fraction form
    28.15/42.17 = 18.53/x
  3. Step 3: Cross multiply
    28.15x = 42.17 × 18.53
  4. Step 4: Simplify right side
    28.15x = 781.25
  5. Step 5: Solve for x
    x = 781.25/28.15
  6. Step 6: Final answer
    x = 27.76

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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.