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Finding the Fourth Proportional to 57.10, 78.81 and 38.70

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Solution

The fourth proportional to 57.10, 78.81 and 38.70 is: 53.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.10 : 78.81 = 38.70 : x
  2. Step 2: Convert to fraction form
    57.10/78.81 = 38.70/x
  3. Step 3: Cross multiply
    57.10x = 78.81 × 38.70
  4. Step 4: Simplify right side
    57.10x = 3,050.09
  5. Step 5: Solve for x
    x = 3,050.09/57.10
  6. Step 6: Final answer
    x = 53.42

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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.