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Finding the Fourth Proportional to 23.20, 31.94 and 21.18

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Solution

The fourth proportional to 23.20, 31.94 and 21.18 is: 29.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    23.20 : 31.94 = 21.18 : x
  2. Step 2: Convert to fraction form
    23.20/31.94 = 21.18/x
  3. Step 3: Cross multiply
    23.20x = 31.94 × 21.18
  4. Step 4: Simplify right side
    23.20x = 676.22
  5. Step 5: Solve for x
    x = 676.22/23.20
  6. Step 6: Final answer
    x = 29.15

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.