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Finding the Fourth Proportional to 91.99, 138.05 and 55.81

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Solution

The fourth proportional to 91.99, 138.05 and 55.81 is: 83.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.99 : 138.05 = 55.81 : x
  2. Step 2: Convert to fraction form
    91.99/138.05 = 55.81/x
  3. Step 3: Cross multiply
    91.99x = 138.05 × 55.81
  4. Step 4: Simplify right side
    91.99x = 7,704.57
  5. Step 5: Solve for x
    x = 7,704.57/91.99
  6. Step 6: Final answer
    x = 83.75

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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.