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Finding the Fourth Proportional to 120.77, 181.03 and 77.31

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Solution

The fourth proportional to 120.77, 181.03 and 77.31 is: 115.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.77 : 181.03 = 77.31 : x
  2. Step 2: Convert to fraction form
    120.77/181.03 = 77.31/x
  3. Step 3: Cross multiply
    120.77x = 181.03 × 77.31
  4. Step 4: Simplify right side
    120.77x = 13,995.53
  5. Step 5: Solve for x
    x = 13,995.53/120.77
  6. Step 6: Final answer
    x = 115.89

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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.