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Finding the Fourth Proportional to 57.05, 78.74 and 31.18

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Solution

The fourth proportional to 57.05, 78.74 and 31.18 is: 43.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.05 : 78.74 = 31.18 : x
  2. Step 2: Convert to fraction form
    57.05/78.74 = 31.18/x
  3. Step 3: Cross multiply
    57.05x = 78.74 × 31.18
  4. Step 4: Simplify right side
    57.05x = 2,454.95
  5. Step 5: Solve for x
    x = 2,454.95/57.05
  6. Step 6: Final answer
    x = 43.03

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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.