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Finding the Fourth Proportional to 20.94, 31.40 and 6.49

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Solution

The fourth proportional to 20.94, 31.40 and 6.49 is: 9.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.94 : 31.40 = 6.49 : x
  2. Step 2: Convert to fraction form
    20.94/31.40 = 6.49/x
  3. Step 3: Cross multiply
    20.94x = 31.40 × 6.49
  4. Step 4: Simplify right side
    20.94x = 203.85
  5. Step 5: Solve for x
    x = 203.85/20.94
  6. Step 6: Final answer
    x = 9.74

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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.