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Finding the Fourth Proportional to 105.25, 157.87 and 28.21

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Solution

The fourth proportional to 105.25, 157.87 and 28.21 is: 42.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.25 : 157.87 = 28.21 : x
  2. Step 2: Convert to fraction form
    105.25/157.87 = 28.21/x
  3. Step 3: Cross multiply
    105.25x = 157.87 × 28.21
  4. Step 4: Simplify right side
    105.25x = 4,452.72
  5. Step 5: Solve for x
    x = 4,452.72/105.25
  6. Step 6: Final answer
    x = 42.31

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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.