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Finding the Fourth Proportional to 112.39, 168.40 and 71.72

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Solution

The fourth proportional to 112.39, 168.40 and 71.72 is: 107.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.39 : 168.40 = 71.72 : x
  2. Step 2: Convert to fraction form
    112.39/168.40 = 71.72/x
  3. Step 3: Cross multiply
    112.39x = 168.40 × 71.72
  4. Step 4: Simplify right side
    112.39x = 12,078.44
  5. Step 5: Solve for x
    x = 12,078.44/112.39
  6. Step 6: Final answer
    x = 107.47

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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.