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Finding the Fourth Proportional to 57.05, 85.55 and 20.95

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Solution

The fourth proportional to 57.05, 85.55 and 20.95 is: 31.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.05 : 85.55 = 20.95 : x
  2. Step 2: Convert to fraction form
    57.05/85.55 = 20.95/x
  3. Step 3: Cross multiply
    57.05x = 85.55 × 20.95
  4. Step 4: Simplify right side
    57.05x = 1,792.49
  5. Step 5: Solve for x
    x = 1,792.49/57.05
  6. Step 6: Final answer
    x = 31.42

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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.