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Finding the Fourth Proportional to 51.57, 71.15 and 30.85

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Solution

The fourth proportional to 51.57, 71.15 and 30.85 is: 42.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.57 : 71.15 = 30.85 : x
  2. Step 2: Convert to fraction form
    51.57/71.15 = 30.85/x
  3. Step 3: Cross multiply
    51.57x = 71.15 × 30.85
  4. Step 4: Simplify right side
    51.57x = 2,194.98
  5. Step 5: Solve for x
    x = 2,194.98/51.57
  6. Step 6: Final answer
    x = 42.56

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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.