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Finding the Fourth Proportional to 57.20, 85.78 and 30.12

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Solution

The fourth proportional to 57.20, 85.78 and 30.12 is: 45.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.20 : 85.78 = 30.12 : x
  2. Step 2: Convert to fraction form
    57.20/85.78 = 30.12/x
  3. Step 3: Cross multiply
    57.20x = 85.78 × 30.12
  4. Step 4: Simplify right side
    57.20x = 2,583.69
  5. Step 5: Solve for x
    x = 2,583.69/57.20
  6. Step 6: Final answer
    x = 45.17

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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.