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Finding the Fourth Proportional to 91.87, 126.78 and 55.05

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Solution

The fourth proportional to 91.87, 126.78 and 55.05 is: 75.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.87 : 126.78 = 55.05 : x
  2. Step 2: Convert to fraction form
    91.87/126.78 = 55.05/x
  3. Step 3: Cross multiply
    91.87x = 126.78 × 55.05
  4. Step 4: Simplify right side
    91.87x = 6,978.87
  5. Step 5: Solve for x
    x = 6,978.87/91.87
  6. Step 6: Final answer
    x = 75.97

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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.