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Finding the Fourth Proportional to 30.87, 42.55 and 19.96

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Solution

The fourth proportional to 30.87, 42.55 and 19.96 is: 27.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.87 : 42.55 = 19.96 : x
  2. Step 2: Convert to fraction form
    30.87/42.55 = 19.96/x
  3. Step 3: Cross multiply
    30.87x = 42.55 × 19.96
  4. Step 4: Simplify right side
    30.87x = 849.14
  5. Step 5: Solve for x
    x = 849.14/30.87
  6. Step 6: Final answer
    x = 27.51

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.