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Finding the Fourth Proportional to 57.05, 85.60 and 31.39

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Solution

The fourth proportional to 57.05, 85.60 and 31.39 is: 47.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.05 : 85.60 = 31.39 : x
  2. Step 2: Convert to fraction form
    57.05/85.60 = 31.39/x
  3. Step 3: Cross multiply
    57.05x = 85.60 × 31.39
  4. Step 4: Simplify right side
    57.05x = 2,686.98
  5. Step 5: Solve for x
    x = 2,686.98/57.05
  6. Step 6: Final answer
    x = 47.10

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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.