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Finding the Fourth Proportional to 91.87, 137.79 and 57.60

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Solution

The fourth proportional to 91.87, 137.79 and 57.60 is: 86.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.87 : 137.79 = 57.60 : x
  2. Step 2: Convert to fraction form
    91.87/137.79 = 57.60/x
  3. Step 3: Cross multiply
    91.87x = 137.79 × 57.60
  4. Step 4: Simplify right side
    91.87x = 7,936.70
  5. Step 5: Solve for x
    x = 7,936.70/91.87
  6. Step 6: Final answer
    x = 86.39

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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.