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Finding the Fourth Proportional to 21.91, 30.25 and 15.01

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Solution

The fourth proportional to 21.91, 30.25 and 15.01 is: 20.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.91 : 30.25 = 15.01 : x
  2. Step 2: Convert to fraction form
    21.91/30.25 = 15.01/x
  3. Step 3: Cross multiply
    21.91x = 30.25 × 15.01
  4. Step 4: Simplify right side
    21.91x = 454.05
  5. Step 5: Solve for x
    x = 454.05/21.91
  6. Step 6: Final answer
    x = 20.72

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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.