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Finding the Fourth Proportional to 31.59, 47.39 and 20.88

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Solution

The fourth proportional to 31.59, 47.39 and 20.88 is: 31.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.59 : 47.39 = 20.88 : x
  2. Step 2: Convert to fraction form
    31.59/47.39 = 20.88/x
  3. Step 3: Cross multiply
    31.59x = 47.39 × 20.88
  4. Step 4: Simplify right side
    31.59x = 989.50
  5. Step 5: Solve for x
    x = 989.50/31.59
  6. Step 6: Final answer
    x = 31.32

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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.