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Finding the Fourth Proportional to 81.51, 122.30 and 51.10

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Solution

The fourth proportional to 81.51, 122.30 and 51.10 is: 76.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.51 : 122.30 = 51.10 : x
  2. Step 2: Convert to fraction form
    81.51/122.30 = 51.10/x
  3. Step 3: Cross multiply
    81.51x = 122.30 × 51.10
  4. Step 4: Simplify right side
    81.51x = 6,249.16
  5. Step 5: Solve for x
    x = 6,249.16/81.51
  6. Step 6: Final answer
    x = 76.67

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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.