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Finding the Fourth Proportional to 21.96, 33.30 and 21.78

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Solution

The fourth proportional to 21.96, 33.30 and 21.78 is: 33.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.96 : 33.30 = 21.78 : x
  2. Step 2: Convert to fraction form
    21.96/33.30 = 21.78/x
  3. Step 3: Cross multiply
    21.96x = 33.30 × 21.78
  4. Step 4: Simplify right side
    21.96x = 725.27
  5. Step 5: Solve for x
    x = 725.27/21.96
  6. Step 6: Final answer
    x = 33.03

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Why These Related Problems?

These problems maintain the same ratio (1.52) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.