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Finding the Fourth Proportional to 90.81, 125.34 and 55.37

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Solution

The fourth proportional to 90.81, 125.34 and 55.37 is: 76.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.81 : 125.34 = 55.37 : x
  2. Step 2: Convert to fraction form
    90.81/125.34 = 55.37/x
  3. Step 3: Cross multiply
    90.81x = 125.34 × 55.37
  4. Step 4: Simplify right side
    90.81x = 6,940.49
  5. Step 5: Solve for x
    x = 6,940.49/90.81
  6. Step 6: Final answer
    x = 76.43

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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.