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Finding the Fourth Proportional to 71.80, 107.60 and 31.18

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Solution

The fourth proportional to 71.80, 107.60 and 31.18 is: 46.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.80 : 107.60 = 31.18 : x
  2. Step 2: Convert to fraction form
    71.80/107.60 = 31.18/x
  3. Step 3: Cross multiply
    71.80x = 107.60 × 31.18
  4. Step 4: Simplify right side
    71.80x = 3,354.97
  5. Step 5: Solve for x
    x = 3,354.97/71.80
  6. Step 6: Final answer
    x = 46.73

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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.