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Finding the Fourth Proportional to 100.20, 150.31 and 28.05

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Solution

The fourth proportional to 100.20, 150.31 and 28.05 is: 42.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.20 : 150.31 = 28.05 : x
  2. Step 2: Convert to fraction form
    100.20/150.31 = 28.05/x
  3. Step 3: Cross multiply
    100.20x = 150.31 × 28.05
  4. Step 4: Simplify right side
    100.20x = 4,216.78
  5. Step 5: Solve for x
    x = 4,216.78/100.20
  6. Step 6: Final answer
    x = 42.09

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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.