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Finding the Fourth Proportional to 100.20, 150.31 and 31.71

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Solution

The fourth proportional to 100.20, 150.31 and 31.71 is: 47.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.20 : 150.31 = 31.71 : x
  2. Step 2: Convert to fraction form
    100.20/150.31 = 31.71/x
  3. Step 3: Cross multiply
    100.20x = 150.31 × 31.71
  4. Step 4: Simplify right side
    100.20x = 4,765.91
  5. Step 5: Solve for x
    x = 4,765.91/100.20
  6. Step 6: Final answer
    x = 47.56

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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.