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Finding the Fourth Proportional to 31.75, 43.22 and 31.21

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Solution

The fourth proportional to 31.75, 43.22 and 31.21 is: 42.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.75 : 43.22 = 31.21 : x
  2. Step 2: Convert to fraction form
    31.75/43.22 = 31.21/x
  3. Step 3: Cross multiply
    31.75x = 43.22 × 31.21
  4. Step 4: Simplify right side
    31.75x = 1,348.87
  5. Step 5: Solve for x
    x = 1,348.87/31.75
  6. Step 6: Final answer
    x = 42.49

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.