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Finding the Fourth Proportional to 11.21, 16.80 and 10.15

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Solution

The fourth proportional to 11.21, 16.80 and 10.15 is: 15.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.21 : 16.80 = 10.15 : x
  2. Step 2: Convert to fraction form
    11.21/16.80 = 10.15/x
  3. Step 3: Cross multiply
    11.21x = 16.80 × 10.15
  4. Step 4: Simplify right side
    11.21x = 170.52
  5. Step 5: Solve for x
    x = 170.52/11.21
  6. Step 6: Final answer
    x = 15.21

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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.