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Finding the Fourth Proportional to 31.89, 47.85 and 19.05

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Solution

The fourth proportional to 31.89, 47.85 and 19.05 is: 28.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.89 : 47.85 = 19.05 : x
  2. Step 2: Convert to fraction form
    31.89/47.85 = 19.05/x
  3. Step 3: Cross multiply
    31.89x = 47.85 × 19.05
  4. Step 4: Simplify right side
    31.89x = 911.54
  5. Step 5: Solve for x
    x = 911.54/31.89
  6. Step 6: Final answer
    x = 28.58

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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.