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Finding the Fourth Proportional to 57.06, 78.78 and 42.31

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Solution

The fourth proportional to 57.06, 78.78 and 42.31 is: 58.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.06 : 78.78 = 42.31 : x
  2. Step 2: Convert to fraction form
    57.06/78.78 = 42.31/x
  3. Step 3: Cross multiply
    57.06x = 78.78 × 42.31
  4. Step 4: Simplify right side
    57.06x = 3,333.44
  5. Step 5: Solve for x
    x = 3,333.44/57.06
  6. Step 6: Final answer
    x = 58.42

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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.