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Finding the Fourth Proportional to 71.91, 107.90 and 57.56

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Solution

The fourth proportional to 71.91, 107.90 and 57.56 is: 86.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.91 : 107.90 = 57.56 : x
  2. Step 2: Convert to fraction form
    71.91/107.90 = 57.56/x
  3. Step 3: Cross multiply
    71.91x = 107.90 × 57.56
  4. Step 4: Simplify right side
    71.91x = 6,209.90
  5. Step 5: Solve for x
    x = 6,209.90/71.91
  6. Step 6: Final answer
    x = 86.36

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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.