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Finding the Fourth Proportional to 30.75, 42.42 and 20.37

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Solution

The fourth proportional to 30.75, 42.42 and 20.37 is: 28.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.75 : 42.42 = 20.37 : x
  2. Step 2: Convert to fraction form
    30.75/42.42 = 20.37/x
  3. Step 3: Cross multiply
    30.75x = 42.42 × 20.37
  4. Step 4: Simplify right side
    30.75x = 864.10
  5. Step 5: Solve for x
    x = 864.10/30.75
  6. Step 6: Final answer
    x = 28.10

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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.