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Finding the Fourth Proportional to 51.56, 71.11 and 39.90

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Solution

The fourth proportional to 51.56, 71.11 and 39.90 is: 55.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.56 : 71.11 = 39.90 : x
  2. Step 2: Convert to fraction form
    51.56/71.11 = 39.90/x
  3. Step 3: Cross multiply
    51.56x = 71.11 × 39.90
  4. Step 4: Simplify right side
    51.56x = 2,837.29
  5. Step 5: Solve for x
    x = 2,837.29/51.56
  6. Step 6: Final answer
    x = 55.03

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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.