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Finding the Fourth Proportional to 21.95, 30.30 and 12.25

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Solution

The fourth proportional to 21.95, 30.30 and 12.25 is: 16.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.95 : 30.30 = 12.25 : x
  2. Step 2: Convert to fraction form
    21.95/30.30 = 12.25/x
  3. Step 3: Cross multiply
    21.95x = 30.30 × 12.25
  4. Step 4: Simplify right side
    21.95x = 371.13
  5. Step 5: Solve for x
    x = 371.13/21.95
  6. Step 6: Final answer
    x = 16.91

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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.