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Finding the Fourth Proportional to 77.25, 115.90 and 31.62

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Solution

The fourth proportional to 77.25, 115.90 and 31.62 is: 47.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.25 : 115.90 = 31.62 : x
  2. Step 2: Convert to fraction form
    77.25/115.90 = 31.62/x
  3. Step 3: Cross multiply
    77.25x = 115.90 × 31.62
  4. Step 4: Simplify right side
    77.25x = 3,664.60
  5. Step 5: Solve for x
    x = 3,664.60/77.25
  6. Step 6: Final answer
    x = 47.44

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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.